Preheat oven to 425°F. Spray doughnut pan with nonstick cooking spray.
In large mixing bowl, sift together cake flour, cocoa powder, sugar, baking powder and salt. Add buttermilk, eggs, oil and vanilla; mix gently until just combined. (Dough will be thick) Fill each doughnut cup approximately 1/2 full. (I put the dough into a piping bag and piped it because the dough is very thick)
Bake 4-5 minutes or until the tops of the doughnuts spring back when touched. Let cool in pan for 3 minutes before removing. Repeat with remaining batter. Finish doughnuts with desired toppings. (I topped my donuts with chocolate ganache and sprinkles)
Notes
Recipe source: From the back of the Wilton Heart Doughnut Pan package
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.