Frankfurt was the coronation city of the Holy Roman Emperors, and the city has never quite let the matter go. Its most famous cake is a crown. Frankfurter Kranz is a ring of sponge, split into layers and filled with buttercream and red jam, then wrapped completely in Krokant, a crushed caramel and nut brittle that stands in for the gold. The red cherries on top are the rubies. It has been the centerpiece of Hessian coffee tables for generations, the cake that comes out when the occasion deserves more than a plain sponge.

Germany, which takes cake seriously, protects the name: anything sold as Frankfurter Kranz must be made with real buttercream. The traditional buttercream is the German kind, a cooked vanilla custard beaten into soft butter, which is lighter and less sweet than the American frosting of butter and sugar.

It is a project, but a calm and orderly one, with each part made separately and assembled at the end. Bake it the day before a race and it will be at its best by the time the grid forms, which in Germany is also, conveniently, the time for Kaffee und Kuchen.

The ring cake

Ingredients

• 1 cup (225 g) unsalted butter
• 1 cup (200 g) granulated sugar
• 1 teaspoon vanilla extract
• 1/2 lemon
• 1/4 teaspoon fine salt
• 5 large eggs
• 1 3/4 cups (225 g) all purpose flour
• 1/2 cup (60 g) cornstarch
• 2 teaspoons baking powder
• 3 tablespoons (45 ml) whole milk

Method

1. Heat the oven to 350°F (175°C) with a rack in the lower third. Brush the inside of the ring pan generously with soft butter, getting into every corner, then dust it with flour, tap out the excess and set it aside.
2. Beat the butter, sugar, vanilla, lemon zest and salt in a large bowl on medium high speed for 5 minutes, scraping down the bowl once.
3. Add the eggs one at a time, beating for 30 seconds after each and scraping the bowl now and then. If the mixture starts to look curdled, add a spoonful of the flour with the next egg.
4. Whisk the flour, cornstarch and baking powder in another bowl. Add half to the batter and mix on low speed just until it disappears, then add the milk, then the rest of the flour, mixing only until no dry flour remains. Scrape the batter into the pan and smooth the top.
5. Bake for 45 to 50 minutes. Cool in the pan on the wire rack for 15 minutes, then turn it out onto the rack and let it cool completely, at least 1 1/2 hours. Wrap it in plastic wrap if you are keeping it overnight.

The nut brittle

Ingredients

• 3/4 cup (150 g) granulated sugar
• 1 tablespoon (15 g) unsalted butter
• 1 1/4 cups (150 g) hazelnuts or blanched almonds

Method

1. Put the sugar in the small heavy saucepan over medium heat. Do not stir; instead, swirl the pan gently as the sugar melts from the edges inward. Keep going until it is all liquid and a deep amber color, 6 to 8 minutes.
2. Take the pan off the heat, stir in the butter and the chopped nuts with the wooden spoon until coated, then tip everything onto the lined baking sheet and spread it out thinly. Work fast; it sets within a minute. Leave to cool for 20 minutes.
3. Break the brittle into pieces, put them in the freezer bag, push out the air and crush with the rolling pin into coarse crumbs, about the size of rice grains, with a few larger bits.

The German buttercream

Ingredients

• 2 cups (480 ml) whole milk
• 1/2 cup (100 g) granulated sugar
• 1/3 cup (40 g) cornstarch
• 2 large egg yolks
• 2 teaspoons vanilla extract
• 1 1/4 cups (285 g) unsalted butter

Method

1. In a bowl, whisk 1/2 cup (120 ml) of the milk with the sugar, cornstarch and egg yolks until smooth. Bring the rest of the milk to a simmer in the medium saucepan, then pour in the yolk mixture, whisking constantly. Keep whisking over medium heat until it bubbles and thickens, then whisk for 1 minute more. Stir in the vanilla.
2. Scrape the custard into a clean bowl and press plastic wrap directly onto its surface so no skin forms. Leave it at room temperature until it is completely cool, about 2 hours, or until it reads the same temperature as your soft butter.
3. Beat the soft butter on medium high speed for 5 minutes until very pale and fluffy. Stir the custard smooth with a spatula, then add it to the butter one large spoonful at a time, beating well after each addition.

Assembly

Ingredients

• 1/2 cup (160 g) redcurrant jelly or seedless raspberry jam
• 12 to 14 red candied cherries

Method

1. Set the cold cake on the cutting board. With the serrated knife, cut it horizontally into three even layers, turning the cake as you saw so the cuts stay level.
2. Put the bottom ring on the serving plate. Spread it thinly with half the jelly, then with a layer of buttercream about 1/3 inch (8 mm) thick. Add the middle ring and repeat with the rest of the jelly and another layer of buttercream. Put the top ring on, cut side down. Set aside about 1 cup of buttercream in the piping bag for decoration.
3. Spread the remaining buttercream all over the outside and the inner hole with the offset spatula, in a thin, even layer. Chill for 20 minutes to firm it slightly.
4. Set the plate on a baking sheet to catch the crumbs. Take handfuls of crushed brittle and press them gently onto the top, sides and inside of the ring until it is completely covered.
5. Pipe 12 to 14 evenly spaced rosettes of buttercream around the top and set a cherry on each one. Chill for at least 2 hours, then take it out 30 minutes before serving.

More from Germany