Combine: Place all the ingredients in a small saucepan. Stir well. If the mixture is too thick, feel free to add a bit more apple juice, but don't overdo it; it is supposed to be slightly thicker than regular juice.
Simmer: Bring to a boil, turn the heat down to medium-low and simmer for 5 minutes.
Chill: Remove from the heat, let cool completely, then chill.
Make your pumpkin puree: bake ½ small pumpkin at 200 degrees Celsius/ 400 degrees Fahrenheit until soft. Remove the peel, measure 180 g/ 6.5 oz, chop roughly and place in a blender. Add 1 cup water and blend until smooth. If it's not perfectly smooth, add the remaining ingredients and blend again until smooth. Pour into the saucepan and continue with the recipe. Strain the juice through a fine-meshed sieve to make sure it is perfectly smooth.
The apple juice should be unsweetened; otherwise, the pumpkin juice will be too sweet.
Add honey and brown sugar to taste. The apple juice I used was very tart, so this amount was right for me. Add more or less according to taste.