Baking makes these cake-like chocolate donuts easier and lighter than the more traditional fried donuts. Add some sprinkles to the glaze for a special occasion!
Spray the doughnut pan with nonstick cooking spray or lightly grease the cavities.
In a bowl, combine the flour, cocoa, espresso powder (if using) baking soda, and salt; stir or whisk to combine.
In a mixing bowl, whisk the egg with the sour cream, sugar, melted butter, and 3/4 teaspoon of vanilla extract. Add the flour mixture and stir just until moistened.
Spoon the batter into a plastic bag, cut a corner off, and pipe it into the wells of the doughnut pan. Or spoon the batter into the pan.
Bake the doughnuts for 11 to 13 minutes, or until a toothpick inserted into a doughnut comes out clean.
Meanwhile, sift the confectioners’ sugar into a small bowl and add 2 tablespoons of milk and 1/2 teaspoon of vanilla extract. Stir and add more milk, in small amounts, until the desired consistency is reached.
Cool the doughnuts slightly in the pan and then remove them to a wire rack.
Glaze the doughnuts while they are still warm.
Stir the powdered sugar, milk, and vanilla together in a medium bowl.