1 cup unsweetened cocoa powder (not Dutch-process) plus 3 tablespoons for dusting pan
1 1/2 cups brewed coffee
1/2 cup American whiskey
2 sticks (1 cup) unsalted butter, cut into 1-inch pieces
2 cups sugar
2 cups all-purpose flour
1 1/4 teaspoons baking soda
1/2 teaspoon salt
2 large eggs
1 teaspoon vanilla
Special equipment: a 10-inch bundt pan (3 1/4 inches deep; 3-qt capacity)
Accompaniment: lightly sweetened whipped cream
Garnish: confectioners sugar for dusting