1. Preheat your oven to 350°F (175°C) and grease a 9-inch springform pan with butter and breadcrumbs.

2. In a large bowl whisk together 250g all-purpose flour, 200g granulated sugar, and 10g baking powder.

3. In a separate bowl whisk 4 large eggs, 120ml sour cream, and 20g vanilla sugar until well combined.

4. Add 100g softened unsalted butter to the egg mixture and whisk until smooth and even.

5. Combine the wet and dry ingredients in the large bowl and mix until just combined without overmixing.

6. Gently fold in 300g sliced apples and 2 teaspoons ground cinnamon into the batter.

7. Pour the cake batter into the prepared springform pan and smooth the top with a spatula.

8. Sprinkle 50g pearl sugar evenly over the top of the cake.

9. Bake for 45-50 minutes or until a toothpick inserted into the center comes out clean and dry.

10. Remove from the oven and let cool in the pan for 10 minutes before transferring to a wire rack to cool completely.