This is my interpretation of the elegant delicious chocolate truffle cake made at Honold, an old-line pastry shop on Rennweg in the center of Zurich.
One 5- x 10-inch rectangular cake, about 12 to 15 servings
Chocolate Cake Batter
12 tablespoons (1 1/2 sticks) unsalted butter, softened
2/3 cup sugar, divided
6 ounces semisweet chocolate, melted and cooled
8 eggs, separated
1 1/3 cups ground almonds
2/3 cup dry breadcrumbs
1 1/2 pounds semisweet chocolate
2 cups heavy whipping cream
3 tablespoons unsalted butter
3 tablespoons light corn syrup
4 ounces melted semisweet chocolate for finishing
Cocoa powder for sprinkling
One 10- x 15-inch jellyroll pan lined with buttered parchment
- Set a rack in the middle level of the oven and preheat to 350 degrees.
- Beat the butter and half the sugar by machine with the paddle on medium speed until light. Beat in the cooled chocolate and then the yolks, one at a time. Scrape the bowl frequently during the addition of the yolks.
- Combine the almonds, crumbs, and cinnamon and stir them into the batter. Whip the egg whites on medium speed, allowing them to increase in volume until white and opaque. Increase speed and beat the remaining sugar in a stream. Whip the egg whites to a firm peak, just a few seconds longer. Stir a quarter of the whites into the batter, then fold in the rest.
- Evenly spread the batter in the prepared pan. Bake until firm, about 15 to 20 minutes. Slide the cake layer from the pan to a rack to cool.
- For the filing, while the cake is baking, melt the chocolate and set aside. Bring the cream, butter, and corn syrup to a simmer and cool to room temperature. Whisk the cooled cream mixture into the chocolate.
- Cut the layer into three 10- x 5-inch layers and arrange one on a cardboard. Spread with the filling and repeat with the second layer. Place the third layer on the cake and cover the tip and sides with the chocolate filling. Use a pastry bag fitted with a large plain tube to pipe the remaining chocolate filling in diagonal lines on the cake top. Chill briefly.
- Spread the melted chocolate onto the sides of the cake and shake some cocoa over the top. Serve the day it’s assembled.