Step 1

For the chocolate donuts: Preheat the oven to 375 degrees F.

Step 2

Spray a 12-cavity donut pan with cooking spray and set it aside.

Step 3

Whisk together the flour, granulated sugar, cocoa, salt, baking powder and baking soda in a large bowl. Whisk together the coffee, buttermilk, oil, vanilla and egg in a separate medium bowl until combined. Add the wet ingredients to the dry ingredients and mix to combine.

Step 4

Transfer the batter to a piping bag. Fill each cavity with batter until it comes about three-quarters of the way up the sides of the pan.

Step 5

Bake until a toothpick inserted into a donut comes out clean, about 12 minutes. Cool the donuts in the pan for 5 minutes, then remove to a rack and cool completely.

Step 6

For the coffee glaze: Mix together the confectioners' sugar, coffee and milk in a bowl until smooth. If it seems too thick, add more coffee little by little.

Step 7

Dip each donut halfway into the glaze, then allow excess to drip off. Sprinkle the tops with hazelnuts and sprinkles. Let set, about 30 minutes.