Prepare praliné creme: Cut chocolate into smaller chunks, add heavy cream and whiskey and boil over a water bath until chocolate has melted completely. Put in the fridge for at least 2 hours or up to one night. In another bowl cream butter, confectioner's sugar and orange zest together and slowy add the chocolate-whiskey mix. Cream everything together and store at room temperature.

Prepare orange layering: Squeeze 4 of the 8 oranges (should be 350 ml). Peel the other oranges and remove all white pieces of the skin, now fillit the oranges. Take 50 ml of the squeezed orange juice and mix with starch. Let the rest of the orange juice (300 ml) boil together with the sugar and thicken slightly with the starch mix. Let it cool and then add the orange filits.

Prepare biskuits: You have to bake two biskuits one after another. For the first one divide 5 eggs and beat the egg whites until stiff, while beating add 125 g sugar and 1 tbsp. vanilla sugar. In a bowl whisk together 120 g flour, 2 tbsp. cacao powder and 0,5 tbsp. baking powder. Add the egg yorks to the egg white-mix and then sift the flour mix until you get a light and fluffy batter. Repeat exactely the same with the other half of the ingredients.

Preheat oven to 180°C . Prepare two baking pans with baking paper (do not oil the pans!). Fill each pan with the same amount of batter and bake for 30 minutes. Then remove from oven. Remove cake from baking pans and let them cool.

Now divide both cakes in the middle until you get four cake bottoms of the same size. Now start layering by taking the first cake bottom and pour over 2 tbsp. of liquour. Spread with orange layering. Top with the next cake bottom. Repeat this with the other cakes bottoms, if you like you can also use the praliné cream for layering. In the end cover the whole cake with the praliné cream and decorate with orange zest.