Preparation

1. Prepare a 22 cm springform pan and line it with baking paper. Preheat the oven to 170°C.
2. Sift the flour and baking powder into a bowl and mix thoroughly.
3. Separate the egg whites from the yolks. Beat the egg whites until lightly stiff, then gradually add the sugar mixed with the vanilla sugar. Add it in small portions, mixing constantly until the mixture is thick and shiny, and the sugar is completely dissolved.
4. Pour the water into the beaten egg whites and mix briefly. Then, while continuing to mix, add the egg yolks one at a time until a smooth, fluffy mixture forms.
5. Add the dry ingredients in 2–3 additions, gently mixing with a spatula or with a mixer on the lowest speed, just until combined.
6. Pour the batter into the prepared pan and smooth the surface. Bake for approximately 40–45 minutes, until a toothpick inserted into the center of the cake comes out clean.
7. After removing from the oven, gently drop the pan from a height of about 10–15 cm onto a countertop covered with a folded cloth. Then, leave the sponge cake in the pan to cool completely.
8. Remove the sponge cake from the pan only after it has cooled completely. It’s best to bake it a few hours in advance or the day before you plan to use it – this will make it more stable and make it much easier to divide into layers.

Preparing the cream:

1. Place the mascarpone, peanut butter, caramel, and heavy cream in a bowl.
2. Blend all ingredients until smooth, uniform, and fluffy.
3. Spread the finished cream over the previously prepared brownie portions, smoothing the surface.
4. Garnish each portion with fresh blackberries just before serving.