• Preheat the oven: Preheat the oven to 350°F/180°C or 320°F/160°C fan. Line a 12-cup muffin tin with paper liners.

Apples:

• Prepare the apples: Weigh the apples before peeling them. Peel, halve, and core them. Cut 12 thin slices for the tops and toss them with 1 tablespoon of lemon juice. Cut the remaining apples into small cubes and toss them with the remaining lemon juice.

  9 oz apples + 2 tablespoons lemon juice, divided

Topping:

• Make the cinnamon sugar: Mix the granulated sugar with 2 teaspoons of cinnamon in a small bowl. Set aside.

  2 tablespoons granulated sugar + 2 teaspoons cinnamon

Batter:

• Mix the dry ingredients: Combine the flour, baking powder, brown sugar, salt, and remaining 2 teaspoons of cinnamon in a medium bowl.

  2 cups all-purpose flour + 3 teaspoons baking powder + ¾ cup brown sugar + 1 pinch of salt + 2 teaspoons cinnamon
• Mix the wet ingredients: Whisk the eggs, oil, milk, and vanilla in a large bowl.

  2 eggs + ½ cup vegetable oil + ⅔ cup full-fat milk + 1 teaspoon vanilla extract
• Make the batter: Add the dry ingredients to the wet ingredients and fold just until combined. Fold in the chopped apples. Don’t overmix.
• Fill the tin: Divide the batter between the muffin cups. Place one apple slice on each muffin and press it lightly into the batter. Sprinkle with the cinnamon sugar.

Bake:

• Bake for 20–23 minutes or until golden and a toothpick inserted into the batter comes out clean.
• Cool: Let the muffins cool in the pan for 5 minutes, then transfer them to a wire rack.