Ingredients
- 4 oz. bittersweet chocolate, finely chopped
- 1/2 cup sour cream
- 1 cup firmly packed light brown sugar
- 2 cups all-purpose flour
- A good pinch of salt
- 3 tablespoons unsweetened cocoa powder
- 1 teaspoon baking soda
- 1 stick unsalted butter, at room temperature
- 1 cup sugar
- 2 very large eggs, separated
- 1 teaspoon vanilla extract
- 3/4 cup water, at room temperature
Preparation
Step 1
Prepare 3 8-inch cake pans or 2 9-inch pans. Butter the bottoms and line with parchment paper, then butter the parchment.
Put the chopped chocolate, sour cream, and brown sugar into a heavy saucepan and set over very low heat. Stir occasionally until melted and smooth but don’t let the mixture become hot. Remove from the heat and set aside until needed.
Sift the flour with the salt, cocoa, and baking soda onto a sheet of wax paper and set aside.
Put the butter into a bowl and, using a wooden spoon or electric beaters, beat until creamy. Gradually beat in the sugar. Beat well, then beat in the egg yolks one at a time, followed by the vanilla extract. Mix in the flour mixture, 1 tablespoon at a time, alternately with the water (if using the mixer, use low speed and mix as little as possible). When thoroughly blended, work in the melted chocolate mixture. Beat the egg whites until stiff, then gently fold into the mixture with a large metal spoon.
Spoon the mixture into the prepared pans, to fill evenly, then bake in a preheated oven at 350°F for 25 minutes for the smaller cakes or 30 minutes for the larger ones. The cakes are cooked when they spring back when gently pressed in the center and have slightly shrunk away from the sides of the pans.
Let cool for 5 minutes, then invert onto a wire rack, remove the parchment paper, and cool completely.
Frost as desired, or just top with whipped cream.