German Crown Cake (Frankfurter Kranz)

For the sponge cake:

The cake may be prepared a day in advance. It will be easier to cut the next day anyway.

Preheat oven to 390°F (200°C). Grease and flour a fluted tube pan (bundt pan, Kranzform).

Beat the egg whites with the cold water until foamy. While beating, slowly add sugar. Next, beat in the egg yolks, vanilla extract, and rum.

Sift together corn starch, flour, and baking powder. Slowly mix it into the egg batter with a spoon.

Ladle the batter into the cake pan and bake for 25 minutes. Leave it in the pan for 5-10 minutes. The cake will shrink the slightest bit and may then be easily removed from the pan. (It will look like a large donut—don’t worry, that’s what you’re looking for. The buttercream will add height to the cake.)

Let the cake cool thoroughly before cutting it twice, lengthwise. The single layers will be about an inch thick.

For the buttercream:

It is important that butter and all of the other ingredients have the same temperature to prevent the buttercream from splitting, so take the butter out of the fridge right away.

In a medium saucepan, prepare the pudding with the milk and the sugar, according to the package instructions (if your pudding mix already contains sugar, merely add about 2 additional tablespoons sugar to the finished buttercream). Place the saucepan in a cold water bath and sprinkle the pudding’s surface with sugar to prevent a skin from forming (alternatively, press some cling film lightly against the pudding’s surface). Once cooled, stir the pudding until smooth. If there are any lumps, force it through a sieve.

Once the butter and the pudding are both at room temperature, whip the butter for about 15 minutes. When it has become white and fluffy, switch to the paddle attachment and add the pudding, about 2 tablespoons at a time, at low speed.

Once all the pudding has been incorporated, stir in the vanilla extract and rum.

To assemble the cake:

Spread the bottom cake layer with 3 tablespoons of jelly. Cover this with a little less than a third of the buttercream and carefully place the middle cake layer on top. Spread this layer with the rest of the jelly and another almost-third of the buttercream. Carefully put the top cake layer in place. Cover the cake with the remaining buttercream, reserving about 2/3 cup for decorating.

Cover the buttercream with the brittle on all sides.

Now pipe 14 dollops of buttercream all around the rim of the cake and top each one with a cocktail cherry. (The cake in the picture was decorated with suger crystals because I made it for my grandparents’ diamond wedding anniversary.)

Put in the fridge until ready to serve, but for at least three quarters of an hour until the buttercream firms up.

Done. Enjoy!

Tips:
– If the buttercream should split, you can try heating (but not browning) a tablespoon of butter and quickly mixing it through the split buttercream.
– There are many ways to cover a cake in hazelnut brittle granules. For the top, I just sprinkle the brittle on. For the outside, I like to fill the palm of my hand with brittle and carefully pat it onto the buttercream, moving my brittle-filled palm from top to bottom. The middle of the cake is best covered by throwing the brittle onto the cake at an angle.
– If you can’t find hazelnut brittle granules, you can also use almond slivers, coarsely ground hazelnuts, or maybe white chocolate shavings.
– The cake keeps well in the fridge for up to three days. I find it’s best on the second day.