
Break the eggs into a large bowl and beat with a mixer at maximum speed for 5-7 minutes. The egg mixture should turn white and double in volume. Add sugar and continue beating until the mixture becomes snow-white and shiny.

Add the sifted flour and mix with a spatula using firm but gentle circular movements from top to bottom. Do not mix for too long, as the dough may become too compact and lose its airiness.

Once the lumps of flour have disappeared, transfer the dough into the pan, smooth the surface and place in a preheated oven for 30-35 minutes. The finished sponge cake is always with an even mound, golden brown in color.
Remove the sponge cake from the pan when it has cooled completely. Carefully run a knife along the sides and separate the sponge cake.

Prepare the cream. Beat the butter with condensed milk and vanilla sugar with a mixer for 5-7 minutes.

Start assembling the cake. Cut the cooled sponge cake into 2 parts and grease with the prepared cream. For better soaking, grease the edges of the cake. Decorate the top of the cake with berries and leave the cake in the refrigerator for a few hours so that the cream thickens and the sponge cake soaks.