"This makes a dark, moist, fine-crumbed cake that needs nothing else! It's well worth the time to bloom, or dissolve, the cocoa. It brings out the chocolate flavor more. It does not give a mocha flavor, just makes the chocolate flavor deeper."
Preheat oven to 350 degrees F (175 degrees C). Grease a fluted tube pan (such as Bundt(R)) with cooking spray.
Mix cocoa powder and hot coffee together in a bowl. Whisk in milk to thin and cool mixture; be sure cocoa is dissolved.
Stir flour, salt, and baking powder together in a bowl.
Cream sugar, butter, and cream cheese together in a bowl using an electric mixer until white and fluffy like frosting, about 5 minutes. Mix in vanilla extract. Add eggs and egg yolks, 1 at a time, mixing completely after each addition. Add half the flour mixture; mix until incorporated. Stir in the cocoa-milk mixture; add the remaining flour mixture. Blend well. Pour batter into the prepared pan.
Bake in the preheated oven until a toothpick inserted into a few places comes out dry, 70 to 90 minutes.