All ingredients for the cake should be at room temperature. Mix the butter with a blender, gradually adding sugar. When the mass becomes fluffy, add one egg at a time, mixing to combine the ingredients. In a separate bowl, mix the two flours with the baking powder. Sift the dry ingredients into the butter and egg mixture. Mix gently until combined.
Heat up the oven to 200° C (390° F). Cover a 20 cm x 20 cm square baking tray with baking paper and place half of the dough on the tray. Place the raspberries on top of it. Add cocoa and milk to the rest of the dough. Cover the mixture with fruits. Bake for 20-25 minutes. Leave the baked dough to cool down.
Pour 400 ml of cold milk into a tall dish. Pour in the contents of the bag and mix at the highest speed for about 3 minutes. Put the finished cream on the baked dough.
Icing: Immerse the bag in hot water for 5-10 minutes. When the icing becomes liquid, carefully remove the bag and squeeze several times to even out the structure of the icing. Cut off the corner of the package. Pour the chocolate icing over the cooled dough and set aside until the icing hardens. Bon appetit!