Preheat oven to 400 degrees F. Grease a 6-slot donut pan with nonstick cooking spray and set aside.
In a medium sized bowl, mix together dry ingredients, including flour, cocoa powder, baking powder, espresso powder, and salt, along with your sugar.
In a small bowl or glass measuring cup, mix together your wet ingredients: milk, egg (beaten), yogurt, oil, and vanilla.
Pour your wet ingredients into the flour mixture, stirring just until combined and mixture is smooth.
Spoon or pipe your donut batter into your donut pan--I typically use a spoon and even out the batter with my finger, but using a piping bag is much neater.
Bake your donuts for 9-11 minutes. You'll be able to tell that they're done when you can press your finger into a donut and it springs back without leaving an indentation.
After letting the donuts cool for a bit, make your glaze: melt chocolate chips in a microwave safe bowl, microwaving for 30 second intervals and stirring in between. Add in your milk and stir until smooth.
Carefully dip the tops of donuts in the glaze, top with chocolate sprinkles, then let cool again and enjoy!