SERVES 8
If you have cold brewed coffee on hand, it can be used in place of the instant coffee and water, but to make sure it isn’t too strong, use 1 cup of cold coffee mixed with ½ cup of water. Serve the cake warm with vanilla or coffee ice cream.
2 |
teaspoons instant coffee powder (see note) |
1½ |
cups water |
1 |
cup (7 ounces) granulated sugar |
⅔ |
cup Dutch-processed cocoa powder |
⅓ |
cup packed (2⅓ ounces) brown sugar |
6 |
tablespoons (¾ stick) unsalted butter |
2 |
ounces bittersweet or semisweet chocolate, chopped |
¾ |
cup (3¾ ounces) unbleached all-purpose flour |
2 |
teaspoons baking powder |
⅓ |
cup whole milk |
1 |
tablespoon vanilla extract |
¼ |
teaspoon table salt |
1 |
large egg yolk, at room temperature |
1. Adjust an oven rack to the lower-middle position and heat the oven to 325 degrees. Lightly grease an 8-inch square glass or ceramic baking dish. Stir the instant coffee into the water; set aside to dissolve. Stir together ⅓ cup of the granulated sugar, ⅓ cup of the cocoa, and the brown sugar in a small bowl, breaking up large clumps with your fingers; set aside. Melt the butter, the remaining ⅓ cup cocoa, and the chocolate in a small bowl set over a saucepan filled with 1 inch of barely simmering water; whisk until smooth and set aside to cool slightly. Whisk the flour and baking powder in a small bowl to combine; set aside. Whisk the remaining ⅔ cup granulated sugar, the milk, vanilla, and salt in a medium bowl until combined; whisk in the egg yolk. Add the chocolate mixture and whisk to combine. Add the flour mixture and whisk until the batter is evenly moistened.
2. Pour the batter into the prepared baking dish and spread evenly to the sides and corners. Sprinkle the cocoa-sugar mixture evenly over the batter (the cocoa mixture should cover the entire surface of the batter); pour the coffee mixture gently over the cocoa mixture. Bake until the cake is puffed and bubbling and just beginning to pull away from the sides of the baking dish, about 45 minutes, rotating the pan halfway through the baking time. (Do not overbake.) Cool the cake in the dish on a wire rack for about 25 minutes and serve.