Potato Pastries (Chocolate Sponge Cake)

Separate the egg whites from the yolks, dividing the sugar into two equal parts.

Whip the first part of the sugar with the egg whites until stiff peaks form, and beat the second part with the yolks until pale and fluffy.

Gently fold the whipped whites into the yolks in 2-3 batches using a spatula, moving from the bottom up.

Sift in the flour and cocoa powder to the mixture in 2-3 batches, folding gently in the same manner.

Pour the batter into a 9-inch (23 cm) baking pan lined with parchment paper.

Bake in a preheated oven at 350ÞgF (180ÞgC) for 30-40 minutes until a toothpick inserted comes out clean.

Let the sponge cake cool completely.

Beat room-temperature butter with condensed milk until smooth and creamy.

Process the sponge cake into fine crumbs using a blender.

Combine the crumbs with the prepared frosting and chill in the refrigerator for at least half an hour.

Shape the pastries with your hands and roll them in cocoa powder.