Hagrid's Monster Book of Monsters cake is a delicious buttercream cake decorated to look like Harry Potter`s famous school book.

The fall is here, and Christmas is approaching fast, and that always puts me in the mood to read the Harry Potter books again and binge-watch all the films.
Jump to recipe
- Hagrid's Monster cake
- Ingredients for the cake
- Ingredients for the decoration
- How to make Hagrid's Book of Monsters cake?
- Tips to avoid the buttercream curdling
- What to do when the buttercream curdles anyway?
- Assemble the cake
- Decorate
- More Harry Potter recipes
- Recipe
- Monster Book of Monsters Cake – Harry Potter Recipe
Hagrid's Monster cake
I baked this book a few months ago as part of a wonderful project I had for five months or so: cooking and baking as many Harry Potter recipes as I could, so to speak. And I did cook and bake like a champion! There are over fifty recipes.
This monster book of monsters cake is not exactly the easy peasy everyday kind of cake that you will bake on a whim. It is not that difficult either, but it requires a bit of preparation and patience. However, if you want to make a fan happy, this is the thing to bake.
Ingredients for the cake
Buttercream
- The book is a regular buttercream cake baked on baking trays and stacked with buttercream.
- I used a German buttercream filling for this monster cake because we all like this kind of buttercream better than the American-style one. Not that I don't like the American one, but when I need buttercream in such large quantities, I find the American buttercream too sweet and dominant.
- However, you can certainly use American buttercream instead; it is just a matter of taste. And American buttercream is easier to make anyway, with no cooking and waiting times involved.
- German buttercream is made by mixing butter, sugar, and pudding, which makes it finer and less sweet. However, it is unsuitable for covering a cake with fondant. The buttercream I used and the whole monster cake are huge versions of the famous German Frankfurter Kranz.
Butter:
- When making the buttercream, I recommend using unsalted European-style butter, which has a higher fat content and less water. This will ensure the buttercream has just the right taste and consistency.
Vanilla pudding:
- I used Dr. Oetker vanilla pudding powder, Dr. Oetker Vanilla Pudding 3 Pack, to make the buttercream, the sort that needs cooking, so there is no instant pudding. (the Amazon affiliate link opens in a new tab).
- However, use the sort of pudding powder available in your country; just make sure it is the sort you must cook with milk and sugar yourself.
- One packet of Dr. Oetker pudding powder contains 37 g/ 1.3 oz powder, which is cornstarch with a pinch of salt and vanilla flavor. So, just in case you cannot find this pudding powder, replace it with the same amount of cornstarch and salt and add some drops of vanilla aroma or 1 teaspoon of pure vanilla extract.
- You can add more vanilla flavor to the finished buttercream if you want a more dominant vanilla taste. I always add some.
- One packet of this pudding powder needs to be cooked with 500 ml/ 2 cups milk and some sugar, but we will get into these cooking details below.
Jam:
- I spread some jam between the layers. It is also the typical way of making Frankfurter Kranz.
- When making the Kranz, I would normally use red currant jelly; in the case of this monster book of monsters, I used plum butter, which is less sweet than regular jam. Considering how sweet the rest was, I thought that was a good idea.
- It was a good idea, so whatever jam, jelly, or fruit butter you decide to use (and you can take really whatever you like), do use a tarter kind. It will cut really nicely through the sweetness.
Chocolate frosting
- I used an American frosting recipe, which I was able to pipe.
- Just make sure that you use unsweetened cocoa powder when making the frosting.
Ingredients for the decoration
- Things get a bit trickier here; there are a few things you will probably not just have lying around.
- I needed to order a grass piping tip Wilton No.233 Decorating Tip (the Amazon link opens in a new tab) to make the fur. I searched for alternatives but couldn't find anything better. (Amazon affiliate link).
- You will also need a small rolling pin, a black food decorator pen, a small fork, and a small clean paintbrush.
- To make the tongue, you will also need small amounts of pink and black fondant, which you can either buy already colored or color yourself if you have the gel food coloring needed for this task.
- To make the eyes, I used round chocolate bonbons, something like Maltersers, large Sprinkles, or M&Ms. But you could also make the eyes using leftover black fondant, for instance.
How to make Hagrid's Book of Monsters cake?
The pudding
- Start with the pudding, as it will need time to reach room temperature. You can make the pudding the evening before you make the cake, cover it with cling film directly on the surface to prevent it from forming skin, and let it on the counter until the next day. This way, you can be sure it has the right temperature.
- Remember to take the butter out of the fridge several hours before you need it for the pudding buttercream. It also needs to be at the exact same temperature as the pudding, so room temperature.
- I followed the packet's instructions to cook the pudding; do make sure to read those.
- If using cornstarch instead of pudding powder, mix 37 g/ 1.3 oz cornstarch with a small pinch of salt. Proceed exactly as described in the recipe below, adding 1 teaspoon of pure vanilla extract or a few drops of vanilla aroma to the hot pudding.
The cake
- Make the batter as instructed in the recipe below.
- Line two baking sheets (30x40 cm/ 12x15 inches) with baking paper and divide the batter equally between the two trays. Bake the cakes in a convection (hot-air/fan) oven for 15-20 minutes or until golden. Let cool completely.
- The cakes can also be made one day in advance. Once cool, cover well with cling film to avoid them drying out until the next day.
The buttercream
To make the buttercream make sure that both the pudding and the butter have the same temperature, which is room temperature. If their temperature is different the buttercream might curdle.
Tips to avoid the buttercream curdling
Temperature. As mentioned above, pudding and butter must be at room temperature.
Butter: Make sure you use unsalted butter; I don't know about other countries, but in Germany, unsalted butter is called Süßrahmbutter – sweet cream butter.
Beat the butter until very light and fluffy, at least two minutes.
Only add the pudding to the butter one tablespoon at a time; don't rush it. Only add the next spoon of pudding to the bowl when the previous one has been completely incorporated, but don't over-mix. Make sure that the pudding is incorporated by mixing it shortly and adding the next tablespoon.
Don't lick your fingers or mix attachments, and touch the buttercream with these fingers or attachments. The spit might cause it to curdle as well.
What to do when the buttercream curdles anyway?
- I had this problem a few times in the beginning, many years ago. I didn't know how to fix it, so I just used the curdled mixture. It didn't look that nice, but it still had the same good taste. However, I soon discovered that there are ways to deal with that issue.
- Place the buttercream into a bowl and place this bowl on bain-marie. The water should not be too hot. Heat very slowly; it will slightly begin to melt underneath, but don't let it melt. Keep mixing with a hand-held mixer on high speed until it becomes smooth again. This miracle will happen very fast.
- Remove the bowl from the bain-marie and keep beating for a few seconds more.
- It always worked for me!
Assemble the cake
- Cut each sheet cake into two equal parts. Trim the edges and make sure they are the same size.
- Place one slice on a board or a rectangular serving platter. Reserve ⅓ of the vanilla buttercream to cover the edges.
- Cover the first slice with half of the jam and some buttercream. Cover with a second slice and only with buttercream. Place the third slice on top and cover it with the remaining jam and buttercream. Place the last slice on top and press lightly to stabilize the cake.
- Use about half of the remaining vanilla buttercream to thinly cover the edges of the cake. There is no need to cover the top, as you will pipe the chocolate frosting on top. Place in the refrigerator for about half an hour or until set.
- In the meantime, prepare the chocolate frosting, the tongue, and the eyes of the Monster Book of Monsters cake.
The chocolate frosting
- Cream the butter briefly in a mixer with a paddle attachment. Stop the mixer and sift the icing sugar, the unsweetened cocoa powder, and the salt on top of the butter. Continue mixing at the lowest speed until the icing sugar is incorporated. Add vanilla extract or vanilla aroma to taste.
- Add 1 tablespoon of the milk and mix the frosting on medium-high speed for about 3 minutes. If the mixture seems too stiff for piping, you can add the second tablespoon of milk.
- Place the frosting in a piping bag fitted with the grass piping tip.
Decorate
- To make the tongue, knead the pink fondant with a little shortening until pliable. Roll it thinly on a smooth surface and cut a long stripe about 13 cm/ 5 inches long and 3,5 cm/ 1.4 inches wide. Cut the tongue tip to resemble a snake's tongue (see picture).
- Knead and thinly roll the blue fondant as well. Cut out four very small rounds, paint the black pupil with the food decorator pen, and stick the pupil onto the Maltesers with some frosting.
- When ready to decorate, take the "book" out of the fridge; it should be sturdy by now. Read the recipe for more details on decorating the cake.
- Keep refrigerated until ready to serve.
I hope you like this monster book cake. If you like Harry Potter, you might want to check some of the other Harry Potter recipes I posted on the blog about 2 years ago, one of them the Harry Potter's Pumpkin Patties is one of the most popular recipes on the blog, especially in autumn and winter.
More Harry Potter recipes
Recipe
Monster Book of Monsters Cake – Harry Potter Recipe
Ingredients
- Cake:
Cake:
- 6 eggs
- 300 g/ 10.5 oz/ 1 ½ cups sugar
- 300 ml/ 10.1 fl.oz/1 ¼ cups buttermilk
- 300 ml/ 10.1 fl.oz/ 1 ¼ cups rapeseed oil neutral taste
- 450 g/ 1 lbs/ 3 ⅔ cups cake flour
- 4 ½ teaspoons baking powder
Filling:
- 500 ml/ 17 fl.oz/ 2 cups milk
- 1 packet vanilla pudding powder Note
- 40 g/ 1.4 oz/ scarce ¼ cup sugar
- vanilla aroma or vanilla extract to taste
- 300 g/ 10.5 oz/ 1 ¼ cups unsalted butter at room temperature
- about 6 tablespoons plum blackberry or black currant jam (more or less as needed)
Chocolate frosting:
- 120 g/ 4.2 oz/ ½ cup unsalted butter at room temperature
- 220 g/ 7.7 oz/ 1 ¾ cups icing sugar
- 25 g/ 0.9 oz/ ¼ cup unsweetened cocoa powder
- ¼ teaspoon salt
- vanilla aroma or vanilla extract to taste
- 1-2 tablespoons milk
Decoration:
- 1 small piece of pink fondant
- 1 very small piece of blue fondant
- some shortening
- 4 round chocolate bonbons Maltesers or similar sweets
- 1 teaspoon unsweetened cocoa powder
Tools:
- small rolling pin
- black food decorator pen
- small fork
- clean small paint brush
- grass piping tip Wilton no. 233
Instructions
Pudding:
- Prepare the pudding well in advance as it will need several hours to reach room temperature. You can make it the day before, place some cling film directly over the surface and let it on the counter overnight.
- When making the pudding (either with bought powder or your own cornstarch mixture, measure the 500 ml/ 2 cups milk needed directly in a pot. Remove about 6 tablespoons of the milk from this amount and place those into a small bowl. Place the pot with the milk on the heat and slowly bring to a boil. In the meantime, whisk the remaining milk with the sugar and the pudding powder.
- When the milk on the hob has come to a boil, slowly pour the pudding mixture into the hot milk while whisking continuously. Let bubble once or twice and remove from the heat. Place a piece of cling film directly over the surface of the pudding and let the pudding come to room temperature, preferably overnight.
- If using cornstarch instead of pudding powder, mix together 37 g/ 1.3 oz cornstarch with a small pinch of salt. Proceed exactly as described above, adding 1 teaspoon pure vanilla extract or a few drops vanilla aroma to the hot pudding.
Cake:
- Preheat the fan/convection oven to 160 degrees Celsius/ 320 degrees Fahrenheit. Line two baking trays (30x40 cm/ 12x15 inches) with baking paper.
- Beat the eggs and the sugar well until light and fluffy, about 3-4 minutes. Add the buttermilk and the oil to the mixture by turns while mixing all the time.
- Mix the flour and baking powder together and sift them over the egg mixture. Incorporate.
- Divide the mixture between the prepared baking trays and bake for about 15 to 20 minutes or until golden. Let cool completely.
Buttercream:
- To make the buttercream both butter and vanilla pudding should have room temperature.
- Mix the butter until very light and fluffy, at least 2 minutes. Start adding the vanilla pudding to the butter one tablespoon at a time, only adding the next tablespoon when the one before is completely incorporated. Add vanilla extract or vanilla aroma to taste.
- Read the blog post for more information on making the buttercream, tips for avoiding the buttercream from curdling, and what to do if the buttercream curdles anyway.
Fill the cake:
- Cut each cake into two equal parts. Trim the edges of the cake and make sure they have exactly the same size. Place one cake slice on a board or a rectangular serving platter.
- Keep ⅓ of the vanilla buttercream for covering the edges of the cake.
- Cover the first cake sheet with half of the jam and some buttercream. Cover with a second sheet of cake and cover it only with buttercream. Place the third cake sheet on top and cover it with the remaining jam and with buttercream. Place the last sheet of cake on top and press lightly to stabilize the cake.
- Use about half of the remaining vanilla buttercream to thinly cover the edges of the cake. There is no need to cover the top of the monster cake with buttercream, as you will pipe the chocolate frosting on top.
- Place the cake in the refrigerator for about half an hour or until set. In the meantime prepare the chocolate frosting, the tongue, and the eyes of the cake.
Chocolate frosting:
- Cream the butter for a few minutes in a mixer with a paddle attachment. Stop the mixer and sift the icing sugar, the unsweetened cocoa powder, and the salt on top of the butter. Continue mixing on the lowest speed at first until the icing sugar is incorporated. Add vanilla extract or vanilla aroma to taste.
- Add 1 tablespoon of the milk and mix the frosting on medium-high speed for about 3 minutes. If the mixture seems too stiff for piping, you can add the second tablespoon milk.
- Place the frosting in a piping bag fitted with the grass piping tip.
Tongue and eyes:
- Knead the pink fondant with a little shortening until pliable. Roll it thinly on a smooth surface and cut a long stripe about 13 cm/ 5 inches long and 3,5 cm/ 1.4 inches wide. Cut the tip of the tongue to resemble a snake's tongue (see picture).
- Knead and thinly roll the blue fondant as well. Cut out four very small rounds, paint the black pupil with the food decorator pen and stick the pupil onto the Maltesers with a bit of frosting.
Assemble:
- Take the cake out of the fridge. Use the remaining vanilla buttercream to cover the edges of the cake with a second layer of buttercream. Trace the pages of the cake on three of the cake's sides and on the fresh buttercream using a small fork.
- Place the cocoa powder into a small bowl and lightly brush the pages of the book with the clean and dry paint brush to give the book an old, battered look.
- Place the tongue on the cake.
- Pipe the chocolate frosting on the cake, going around the edges first and filling the top of the cake. Pipe some chocolate frosting at the base of the cake, on the board, as well. Only pipe the back of the cake with frosting when the cake is completely finished, if you have enough frosting left.
- Place the eyes on the cake as seen in the picture. Pipe some more frosting around the eyes to give them a bushy look.
- Pipe the leftover frosting on the back of the cake, if you wish.
- Keep refrigerated until ready to serve. This is a large cake and it will serve at least 16 people, probably more if you will cut smaller slices. It is very rich, so a small slice goes a long way.
Linn says
Just wanted to leave a comment to thank you for this brilliant recipe. I made the cake for my son's 7th birthday and he (and the rest of the family) LOVED the cake. It was so delicious and I felt super proud having made a cake that looked pretty impressive!
Adina says
I am so happy to hear it, Linn. Thank you so much for the feedback and review.
Thao @ In Good Flavor says
My husband and I are huge Harry Potter fans. We have watched all the movies umpteenth times. I often like to put it on as background when I'm working in the kitchen. It's one of those few things I never tired of. I can't tell you how stinkin' cute and incredibly delicious this looks, Adina!! <3
Kelly | Foodtasia says
This cake looks so awesome! My kids would love it! Very interesting to read about German buttercream. I avoid the American one because it's way too sweet for me. The German buttercream sounds perfect!
Anca says
Your cake looks stunning. I remember your Harry Potter inspired bakes, those were a fun read.