Sift together the flour, cocoa powder, and baking powder. Set aside.
In a large mixing bowl, cream together the butter and sugar until light and fluffy. Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract.
Gradually add the dry ingredients to the creamed mixture alternating with the coffee and milk, starting and ending with the flour mixture. Mix until just combined.
Grease and flour a 10-inch Bundt pan. Pour the batter into the prepared pan.
Bake in the preheated oven for about 60-65 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool in the pan for 10 minutes, then turn out onto a wire rack to cool completely. Serve as desired.