Some people like and appreciate flour-less cakes. In many parts of Europe, including the Danubian nations, walnuts are very highly esteemed cake ingredients, and the discovery that walnuts can completely eliminate flour in cake preparation was eagerly welcomed. The result was absolutely delicious: some of the finest cakes that naturally do not contain even a speck of flour.
This is a rich and hearty torte made of chocolate-walnut sponge cake layers and delicious coffee buttercream. I don’t cook the butter with eggs, but add it later at room temperature. (You can try it both ways and see which you prefer.) The filling I get is lighter in shade, which gives the entire torte a lighter appearance
Enjoy!

Cake layers

• 10 eggs
• 2/3 cup/ 4½ oz/ 125 g sugar
• 4 oz/ 100 g bittersweet chocolate
• 9 oz/ 250 g walnuts, finely grated

1. Preheat the oven to 425°F/ 220°C. Line two 9in/ 23cm round baking pans with aluminum foil, parchment or wax paper, or grease and flour the pans.
2. Melt the chocolate: break the chocolate into small pieces and put them into a small saucepan or heatproof dish. Use a larger pot to bring 2in/ 5cm of water to a boil, then set aside for 1 minute. Place the pot with the chocolate into the pot with hot water and wait 5 minutes for the chocolate to melt. Mix until smooth, remove from the hot water, and set aside to cool – mix occasionally.
3. Separate the eggs. Use a large mixing bowl for egg whites and a smaller bowl for egg yolks.
4. Beat the egg yolks and half of the sugar with an electric mixer at high speed for 5 minutes until the mixture is pale and thick and the ribbon stage is reached. Fold the cooled chocolate into the egg yolks using a silicone spatula.
5. Beat the egg whites with an electric mixer (use clean beaters) until soft peaks form. Add the rest of the sugar, one tablespoon at a time, and beat until the sugar dissolves and medium-firm peaks form. Do not beat to the stiff peak stage.
6. Lighten the egg yolk mixture with a third of the egg whites using a silicone spatula. Gently fold the lightened egg yolk mixture back into the rest of the egg whites. Spread a third of the finely grated walnuts over the entire surface of the mixture and carefully fold, preserving the airiness. Repeat until all of the walnuts are uniformly incorporated into the batter. Spread the batter into the prepared pans.
7. Bake for 5 minutes at 425°F/ 220°C, then reduce the oven temperature to 375°F/ 190°C and bake for an additional 20 minutes. Do not open the oven door until the cake layers start to smell good. The cake layers are done baking when their edges begin to separate from the pans, a toothpick inserted in their centers comes out clean, and the noise from the popping air bubbles has stopped. Let the cake layers cool in the pans for 5 minutes. Be careful when removing the cake layers from the pans because they easily break and crumble. Take the cake layers out of the pans and let them cool completely in the aluminum foil. In case you are not using aluminum foil, first run a thin knife around the edges to separate the cake layers from the pans. Then, leave them top side up on a cooling rack or cloth to cool completely.

Filling

• 6 egg yolks (the remaining egg whites are not used for this cake)
• 1 cup/ 8 oz/ 225 g sugar
• 2 teaspoons instant coffee
• 1/2 cup/ 4 oz/ 100 ml whole milk, warm
• 8 oz/ 225 g/ 1/2 lb/ 1 cup unsalted butter

For Decoration

• 2 oz/ 50 g/ 1/8 lb/ 1/4 cup unsalted butter
• 1 teaspoon sugar
• 2 oz/ 50 g chocolate shavings

1. Fill the pot of an improvised double boiler with water and bring it to a simmer (the water should not be in direct contact with the mixing bowl in the next step). Dissolve the instant coffee in the 1/2 cup of warm milk, set aside.
2. Beat the egg yolks and sugar with an electric mixer at high speed in the mixing bowl of the double boiler (see section on "equipment") until the mass is pale and fluffy. Add the milk and coffee and mix well. Place the mixing bowl on the pot with simmering water and beat continuously with an electric mixer for 10 minutes until the mixture begins to thicken and is hot to your finger.
3. Discard the boiling water and fill the pot with cold water for cooling. Place the mixing bowl on the pot (this time the bowl needs to be immersed in the water). Beat the mixture with an electric mixer for 5 minutes until it cools completely, otherwise the warm mixture will melt the butter in the next step.
4. Beat the butter with an electric mixer until creamy. Gradually add the cold egg mixture into the butter, two tablespoons at a time, while continuously beating with a mixer. Make sure to bring the butter mixture to a very smooth stage before another addition of the egg yolk mixture. Keep beating until the mixture is smooth.
   Note: Another interesting way to make a filling with the same ingredients is to mix all of the butter with the egg yolks right at the start and then steam it all together in a double boiler. No extra butter is added later. The resulting filling has a slightly bolder and richer taste and thicker consistency.

Assembling the cake

1. Reserve 1 teaspoon of the filling for decoration and divide the rest into three parts. Place the first cake layer on a serving tray and spread a third of the filling over it. Repeat with the second cake layer and cover the whole cake with the rest of the filling. (You can cut the layers to make a four-layer cake, if you prefer.)
2. For decoration, sprinkle the top of the cake with chocolate shavings. Beat the butter and sugar until the sugar dissolves and the mixture is fluffy. Mix with the reserved filling and use it in a pastry bag fitted with a dot attachment.
3. Keep the cake refrigerated under a dome for up to a week. Remove from the refrigerator thirty minutes before serving.