This simple flourless chocolate cake tastes extra festive with the addition of chestnut purée and a bit of dark rum. To serve alongside the almost-brownie-like cake is a sweet-and-tart kumquat sauce infused with cinnamon, clove and allspice, as well as a dollop of rich whipped mascarpone.
To learn more, read "A Hard Nut to Crack."
Chocolate and Chestnut Cake with Kumquat Sauce and Mascarpone Whipped Cream
Recipe from the Tasting Table Test Kitchen
Yield: 8 to 10 servings
Prep Time: 1 hour and 30 minutes
Cook Time: 1 hour
Total Time: 2 hours and 30 minutes
For the Chocolate and Chestnut Cake:
8 tablespoons (1 stick) unsalted butter, at room temperature, plus more for greasing
Cocoa powder, for dusting
¾ cup chestnut purée
6 ounces semisweet chocolate, finely chopped
1 teaspoon vanilla extract
5 large eggs, separated
¾ cup granulated sugar
2 tablespoons dark rum
¼ teaspoon kosher salt
Powdered sugar, for dusting
For the Kumquat Sauce:
3 cups (about 1 pound) sliced, seeded kumquats
1 cup water
1 cup sugar
½ teaspoon salt
4 whole cloves
3 whole allspice berries
1 cinnamon stick
For the Mascarpone Whipped Cream:
½ cup mascarpone cheese
¼ cup heavy whipping cream
1. Make the chocolate and chestnut cake: Preheat the oven to 350°. Line the bottom of an 8-inch cake pan with parchment paper. Butter the bottom and sides of the pan, then dust with cocoa powder and tap out any excess.
2. In a blender, combine the butter and chestnut purée. Blend on high until the mixture is smooth.
3. In a saucepan over medium heat, bring water to a simmer. Transfer the chestnut mixture and chocolate to a glass bowl; place the glass bowl over the pot. Stir the chestnut mixture until the chocolate has melted and becomes glossy, 4 to 5 minutes. Remove the bowl from the pot and stir in the vanilla extract.
4. In the bowl of a stand mixer, whisk together the egg yolks and ½ cup of the sugar until the yolks have nearly doubled in size and ribbons have formed, 5 minutes. Transfer to a large mixing bowl.
5. Using a rubber spatula, fold the chocolate mixture, rum and salt into the egg yolk mixture and set aside.
6. In a clean bowl of a stand mixer, beat the egg whites until soft peaks form. Continue to beat while gradually adding the remaining ¼ cup of sugar until stiff, glossy peaks form.
7. Fold a third of the whipped egg whites into the chocolate mixture. Fold in the remaining egg whites until there are no streaks, but do not over mix the batter.
8. Pour the batter into the greased and dusted pan and bake for 35 to 40 minutes, or until a cake tester inserted into the center of the cake comes out clean. Transfer to a wire rack and let cool for 20 minutes before serving. Dust the top of the cake with powdered sugar.
9. Meanwhile, make the kumquat syrup: Place the kumquats in a bowl and set aside. In a small saucepan over medium-high heat, combine the water, sugar, salt, cloves, allspice and cinnamon. Bring to a simmer and stir until the sugar dissolves, 2 to 3 minutes. Remove from the heat and allow to cool and infuse for 30 minutes.
10. Strain the infused syrup into a separate saucepan and discard the solids. Add the kumquats and simmer over medium heat until the kumquats are just tender, 10 minutes. Remove from the heat and let cool. Make ahead: Kumquat sauce can be made up to 5 days ahead. After cooling, cover and store in the fridge.
11. Make the mascarpone whipped cream: In a large bowl or in a bowl of a stand mixer, whisk the mascarpone and heavy cream until thick, stiff peaks form.
12. Serve slices of the cake with the kumquat sauce and a dollop of the mascarpone whipped cream.