Prague Cake

Sift the flour together with the cocoa powder.

Separate the egg whites from the yolks.

Whisk the egg yolks with half of the sugar until thick and pale.

Whip the egg whites to stiff peaks, add the remaining sugar, and beat until fluffy.

Gently fold the white and yolk mixtures together, sift in the flour, and mix thoroughly.

Grease a cake pan with butter and dust it with flour.

Pour the batter into the prepared pan.

Bake for 30 minutes at 200°C.

Let the baked sponge cake cool in the pan for 5 minutes, then invert onto a wire rack and leave until completely cool.

Wrap the cooled sponge cake tightly in plastic wrap.

Softening the butter at room temperature.

Mix the egg yolk with water until smooth.

Add the condensed milk and stir well.

Cook over low heat (using a water bath) until thickened.

Chill the mixture.

Beat the softened butter with vanilla sugar.

Gradually incorporate the butter into the cooled condensed milk mixture, beating continuously.

Add the cocoa powder and beat until smooth.

Slice the sponge cake into three layers, spread chocolate buttercream over two of them, and stack to assemble the cake.

Warm the apricot jam, press it through a sieve, and coat the outside of the cake.

Melt the chocolate and butter together in a water bath, then pour the glaze over the cake.