If you're looking for a birthday cake that is different enough to become a party memory but traditional enough to keep the honoree from feeling like a guinea pig, this Mocha Brownie Cake will fit the bill.
I baked this cake this summer from a recipe in Dorie Greenspan's "Baking with Julia." While the length of the recipe might scare off some people, it really was a simple cake to bake and build. The one cautionary note I would include has to do with cooking time. If you overbake the cake, it will be dry and even the moist filling won't redeem you. You'll want to start testing it with a toothpick at about 25 minutes.
The recipe for the ganache calls for strong brewed coffee. If you want to give the filling a distinctive mocha flavor, you'll use coffee that is black enough to border on undrinkable. If you want a hint of mocha in the ganache, your basic strong cup of coffee will do.
The nice thing about this cake is that it really does taste like a brownie with filling. And you get to use the leftover filling for frosting.
You will need a 9-inch, spring-form pan to build the cake. You could bake it in another 9-inch cake pan, or use the spring-form pan, wash it and reuse it.
Mocha Brownie Cake
3/4 cup all-purpose flour
3/4 teaspoon baking powder
1/2 teaspoon salt
4 1/2 ounces semisweet chocolate, coarsely chopped
2 1/2 ounces unsweetened chocolate, coarsely chopped
3/4 stick (3 ounces) unsalted butter
5 large eggs
1 cup sugar
1 teaspoon vanilla extract
3 tablespoons sour cream
1 1/4 cups heavy cream
3 tablespoons unsalted butter
3 tablespoons sugar
12 ounces semisweet chocolate, coarsely chopped
1/4 cup hot strong brewed coffee
For the cake: Position a rack in the center of the oven and preheat to 325 F. Butter a 9-inch round cake pan and dust with flour, tapping out the excess. Set aside.
Whisk together the flour, baking powder and salt in a small bowl and reserve.
Heat an inch of water in the bottom of a double boiler. Place the chocolates and butter in the top of the boiler and heat, stirring occasionally, until the mixture is fully blended and smooth. Remove the pan from the heat.
Put the eggs, sugar and vanilla in the bowl of a mixer fitted with the whisk attachment, or use a hand mixer, and whip on high speed for 4 to 5 minutes, or until the eggs are slightly thickened and doubled in volume. Add the melted chocolate and mix at medium speed for 15 seconds. Don't worry if the chocolate is not full incorporated it will blend as you add the other ingredients. Remove the bowl from the mixer and, working with a rubber spatula, gently but thoroughly fold in the dry ingredients. Give the sour cream a vigorous turn or two to loosen it and fold it into the batter. The batter will be quite thick.
Pour the batter into the pan and use a spatula to smooth and level it. Bake the cake for 45 to 50 minutes, until a toothpick inserted into the center comes out clean. Transfer the cake to a cooling rack and let it cool in the pan for 20 minutes. Turn the cake out onto a cardboard cake round, or the round from a tart pan with a removable bottom, and refrigerate uncovered for 1 hour.
For the ganache: Heat the cream, butter and sugar in a medium saucepan over medium-high heat, stirring frequently, until the sugar is dissolved and the mixture reaches the boiling point. Put the chopped chocolate in a large bowl and pour in the boiling cream mixture and the hot coffee. Set the mixture aside for 5 minutes, then stir until smooth. The ganache must cool thoroughly. You can leave it to cool at room temperature, which could take an hour or so, or you can refrigerate it. The ganache thickens as it cools. You want to use it when it just begins to thicken and can still be poured, rather than spread, over the cake.
For the assembly: Remove the cake from the refrigerator and invert it onto a clean, dry work surface. Working with a long knife, cut the cake into three even layers. Place the top layer of the cake, cut side down, into a 9-inch, spring-form pan whose sides are closed. Pour 1 cup of the ganache over the layer, spreading it to the edges with a spatula. Refrigerate uncovered until set, about 15 minutes. Top with the center layer, pressing it gently into place, and pour over another cup of ganache, again taking care to spread the filling to the edges; refrigerate until set. Place the last layer, cut side down, in the pan, and press down firmly to position it. Refrigerate the cake for at least 1 hour. Cover the remaining ganache with plastic wrap and keep it at room temperature.
To finish the cake, run a knife around the inside edges of the cake pan; release the sides of the spring form. Pour the remaining ganache over the top and around the sides. Allow the icing to set in the refrigerator or at room temperature before cutting the cake.
When she's not writing about foods and gardening, Gwyn Mellinger is teaching journalism at Baker University. Her phone number is (785) 594-4554.