Black Dinah chocolatier Kate Shaffer writes, “If I’m ever asked if I have a signature dessert, this cake is my answer. It consists of four feather-light layers of chocolate genoise, generously soaked with sweet rum syrup. The cake is then filled and covered with an espresso-spiked mascarpone cream, scattered with whole coffee beans, and dusted with cocoa.
The cake made its debut, wrapped in a satiny sheet of chocolate and crowned with Nancy Calvert’s fragrant late-summer roses, at an all-chocolate dinner I gave at the Keeper’s House several years ago. A glorious conclusion to the meal, and an irrefutable showstopper. I have since scaled down the presentation, but the cake is no less delicious because of it.”
Black Dinah Chocolate Tiramisu
Serves 8-10
For the soaking syrup:
½ cup granulated sugar
½ cup dark rum
For the cake:
⅔ cup flour (sift before measuring)
⅔ cup Dutch-process cocoa (sift before measuring)
8 tablespoons unsalted butter
1 tablespoon vanilla
8 large eggs
1⅓ cups granulated sugar
For the frosting:
16 ounces mascarpone cheese
2 cups heavy cream
¼ cup granulated sugar
1 teaspoon vanilla
1 tablespoon instant espresso powder
To make the syrup, combine ½ cup of water and the sugar in a saucepan. Bring the mixture to a boil over medium heat and cook until all the sugar has dissolved. Remove from heat. Allow the syrup to cool completely, and then add the rum and stir. Store the syrup in a glass jar or plastic squeeze bottle in the refrigerator.
To make the cake, grease by hand, or spray with vegetable oil, two 9-by-3-inch round cake pans. Line the cake pans with parchment paper. Preheat the oven to 350 degrees. Sift the flour and cocoa together. Re-sift three more times and set aside. Melt the butter in a small saucepan, until it starts to bubble and a layer of foam forms on the surface. Scrape off the foam with a wide spoon and discard. Pour the melted butter into a medium-size bowl, being careful not to take the cloudy, white milk solids that remain at the bottom of the saucepan. Stir the vanilla into the clarified butter.
Meanwhile, have a pot of simmering water ready. Break the eggs into the bowl of your stand mixer, whisk in the sugar and place the bowl over the simmering water. While stirring gently, heat the mixture until it is a little warmer than room temperature. Remove from heat and immediately begin to beat at high speed with the whisk attachment for 8-10 minutes. The mixture is ready when it falls in ribbons that hold their shape slightly when the whisk is lifted from the bowl. Place the bowl that contains the clarified butter over the simmering pot of water and leave it for a minute or two while you complete the next step.
Remove the mixing bowl from its stand and sift the flour mixture onto the surface of the egg mixture in three additions, folding with a large rubber spatula between additions. Remove the bowl of butter from the simmering pot, and pour roughly 2 cups of the batter into the butter. With a smaller spatula, fold the butter and batter together and then return this mixture to the larger bowl of batter. Fold together.
Empty the batter into the cake pans, smoothing the top with an offset spatula. Bake for 20-30 minutes or until the cake has completely come away from the sides of the pans.
Cool completely before removing the cake from the pans. To make the frosting, beat the cheese, cream, sugar, vanilla, and espresso powder in a stand mixer with the whisk attachment until the cream is smooth and spreadable. Try not to overbeat, as the mixture tends to get grainy and will eventually separate.
To assemble the cake, cut each layer in half so that you end up with four circular layers. Place one layer on your cake plate and douse with the rum syrup (a plastic squeeze bottle works great for this). Allow the cake to soak up the syrup. Slather on a ½-inch layer of frosting, and top with the next layer. Douse this top layer with rum syrup and then frost. Repeat this process for each layer. You will probably not use all the syrup. It will keep in the refrigerator until your next project.
Cover the entire cake with frosting (if necessary, smooth out the sides of the cake by trimming with a long bread knife before frosting). Reserve a little frosting for eight “turbans” on top of the cake. Pipe these on with a pastry bag and a large star tip.
Toss a couple whole coffee beans onto the tip of each turban, and then, using a fine sieve, dust the entire cake lightly with cocoa powder. Refrigerate and serve the cake well-chilled, accompanied by something bubbly to drink.
Purchase Desserted: Recipes and Tales from an Island Chocolatier by Kate Shaffer here.