Frankfurter Kranz, a German Buttercream Cake with caramelized Hazelnuts
The Frankfurt Crown Cake, also known as Frankfurter Kranz is the queen of German buttercream cakes and my grandmother was a master at baking it. There was no special occasion, no family Sunday lunch without this opulent cake on the table. If you're on a diet you should avoid it because as all buttercream cakes, it needs lots of eggs, sugar and butter to transform into a delicious layered sponge cake filled and covered with German vanilla buttercream and sprinkled with caramelised hazelnuts. My Granny's lunches used to start with a green salad with a sugared cream dressing followed by the best beef rouladen (beef olive) filled with prosciutto, gherkin and mustard. While everyone else was worried about how one would manage to eat her traditional Frankfurt Crown Cake so soon at tea time, I was already excited and looking forward to eating my beloved buttercream cake.
The outside of the spongy cake, made with lots of vanilla and eggs, soaks a bit of the cream, which is made of vanilla pudding mixed with butter, that's why the cake is best after 2 days. The aromas have to spread, the vanilla and also the buttery caramelized hazelnuts infuse the cake. It's best to keep it in the fridge but it should always be eaten at room temperature. I didn't manage to wait for a couple days, the cake looked so good, I had to eat it as soon as I sprinkled the last hazelnuts on top. It was great but when I ate a piece on the 3rd day, I was reminded why it's good to be patient. The cake was amazing, it had developed its full deep taste and I understood why this cake was my Granny's famous signature cake.
Sometimes life is just about enjoying a piece of cake, no matter how much butter or eggs were needed to make it. Mother's and grandmother's know that!
Happy Mother's Day!
Frankfurt Crown Cake, Frankfurter Kranz
For a 23cm / 9″ bundt pan you need
For the sponge cake
butter, at room temperature, 200g / 7 ounces
granulated sugar 225g / 8 ounces
a pinch of fresh vanilla
organic eggs 6
plain flour, sieved, 200g / 7 ounces
cornstarch, 100g / 3.5 ounces
baking powder 3 teaspoons
a pinch of salt
dry breadcrumbs to sprinkle the bundt pan
Set the oven to 180°C / 355°F top/ bottom heat. Butter a bundt pan and sprinkle with bread crumbs.
Beat the butter, sugar and vanilla till fluffy, add the eggs, one at a time and continue beating for a few minutes till thick, creamy and light yellow. Combine the dry ingredients and fold gently into the butter egg mixture with a wooden spoon (in batches, combine well in between). Scrape the dough into the bundt pan and bake for 45 minutes or until golden. Check with a skewer, it should come out clean. Let the cake cool for 2-3 minutes before you turn it over onto a wire rack to cool completely. When the cake has cooled off completely, slice it 3 times into 4 layers.
For the buttercream
All ingredients for the buttercream must be at the same temperature (room temperature) to combine well!
butter 250g / 9 ounces
organic egg yolks 4
cornstarch 60g / 2 ounces
granulated sugar 120g / 4.5 ounces
milk 500ml / 17 ounces
a pinch of salt
vanilla bean, slit slightly, 1
Beat the butter for 10 minutes till white and fluffy.
Whisk the egg yolks with the cornstarch, sugar, salt and 50ml / 2 ounces of the milk till well combined.
In a sauce pan, bring the remaining milk together with the vanilla bean to a boil. Take the vanilla bean out, scrape the seeds out of the bean into the milk. Add the egg mixture to the hot milk, whisking well. Take the sauce pan off the heat after 1 minute and continue whisking for 2 minutes till stiff. Fill into a bowl and cover the pudding's surface with cling film.
When the vanilla pudding has cooled off completely, press it through a sieve and mix in batches with the beaten butter, first with a spoon and then with your mixer for a few seconds till nice and creamy.
For the caramelized hazelnuts
hazelnuts, finely chopped, 200g / 7 ounces
granulated sugar 100g / 3.5 ounces
butter 35g / 1.5 ounces
In a large heavy pan, heat up the hazelnuts, sugar and butter on high-medium temperature and roast for around 5 minutes till golden brown and caramelized, stirring constantly. Take off the heat and spread on parchment paper.
Assembling the Frankfurter Kranz
Leave around 1/3 of the buttercream to cover the Frankfurter Kranz and spread the remaining cream on the 3 layers of cake. Start with the bottom one, spread with cream, cover with the next layer of cake and continue with the other layers. When the cake is assembled, spread the remaining cream gently all over the cake and sprinkle with the caramelized nuts on all sides, inside and out.
You can eat the cake right away or be patient and keep it in the fridge for 1-2 days before you serve it.
