Orange Cake with Buttercream
For the orange cake: Grease the springform pan. Melt the butter in a small saucepan. Separate the eggs. Beat sugar and egg yolks until thick. Dust some flour onto the bottom of the pan, then pour in the lukewarm butter. Beat the egg whites until very stiff and carefully fold one-third of it into the egg yolk mixture. Pour in the remaining egg whites and carefully fold. Grate the zest of two oranges and stir in. Pour the cake batter into the mold, smooth and bake for about 30 minutes at 180°C (approximately 350°F). Remove and cool.
For the butter cream: Beat the eggs in a bowl until fluffy wiht an electric mixer, then sprinkle in the sugar. Put into a water bath and beat another 5-7 minutes until it is white and creamy. Cool the cream. Warm the butter in a bowl and beat for 15 minutes at the highest level of the hand mixer until creamy. Scrape out the vanilla beans from the pod and stir them into the butter. Stir in the cooled cream. Melt the chocolate over a water bath and let cool slightly, then mix into the butter cream.
Cut the cake in half horizontally to form two equal layers. Spread some butter cream onto the bottom layer and top with the second cake layer. Top the cake with more butter cream.
Pour the remaining butter cream into a pastry bag and decorate the cake with it. Decorate with pieces of orange zest and cheeries. Refrigerate at least 3 hours before serving.