It’s not clear whether this cake was named after the largest city of Saxony, or its contriver’s family name was Lipcsei / Leipzig, but it’s sure that it’s a 50-60 year old recipe, which was already included in my granny’s cookbook.

Leipzig slices are quite laborious, they consist of two cocoa cake layers made from a kneaded dough and a sponge cake layer, which are sandwiched with a white butter cream. This confection puts your patience to the test, since the cocoa cake layers are hard, and they need time to become soft. You have to wait for 24 hours before you can enjoy it.

Ingredients:
For the dough:

• 300 g (~2 1/2 cups) flour
• 1 tsp baking powder
• 20 g (~2 tbps) cocoa powder
• 50 g (~1/4 cup) sugar
• 100 g (~1/2 cup) butter
• 5 tbsp sour cream
• 1 egg

For the sponge cake:

• 5 eggs
• 5 tbsp flour
• 3 tbsp sugar
• 1 tbsp vanilla sugar
• 1 tsp baking powder
• pinch of salt

For the filling:

• 200 g (~1 cup) butter
• 140 g (~1 cup) powdered sugar
• 4 tbsp flour
• 1 tbsp vanilla sugar
• 500 ml (~2 1/4 cups) milk

For the glaze:

• 100 g (~3 1/2 oz) semi-sweet dark chocolate
• 50 g (~1 3/4 oz) butter

Size of the baking pan and baking sheet: 30×30 cm (12×12 inch)

For the cocoa dough place all ingredients in a bowl and knead into a smooth, pliable dough. Wrap and put it in the fridge for 15 minutes.

Preheat the oven to 180°C / 356°F.

Meanwhile make the sponge cake. Separate the eggs. Whip the egg whites with a pinch of salt until stiff. In a separate bowl beat the egg yolks with sugar and vanilla sugar until thick. Mix in flour and baking powder, then gradually fold the egg whites into the yolk mixture. Pour the batter in a baking pan lined with parchment paper and bake for 20 minutes or until golden brown. Transfer the sponge cake onto a rack and let it cool.

Cut the dough into half and on a floured surface roll out the pieces into two thin rectangles. Transfer the rectangles onto baking sheets lined with parchment paper and bake at 180°C / 356°F for 10-12 minutes. Let them cool.
In a small saucepan combine 4 tablespoons of flour and 1 tablespoon of vanilla sugar, and gradually mix in the milk. Over medium heat cook, stirring constantly, until the mixture thickens. Set aside and let it cool.

Cream butter and powdered sugar together, and combine with the cool flour cream.

Place a cocoa cake layer on a platter and spread half of the cream filling on top evenly. Put the sponge cake on the filling and spread with the remaining cream. Cover with the other cake layer.

Melt dark chocolate and butter, whisk until well combined, and pour the glaze on top of the cake. The cocoa cake layers need to soften; therefore, chill the cake for 24 hours before slicing.