01 -
Whisk flour, cocoa powder, granulated sugar, baking powder, baking soda, salt, and ground cinnamon together in a large bowl until fully blended.
02 -
In a separate bowl, beat eggs, buttermilk, melted butter, and vanilla extract until smooth. Gently add the wet mixture to the dry ingredients and mix until just combined with minimal lumps.
03 -
Cover the dough with plastic wrap and refrigerate for 30 minutes to firm. On a floured surface, roll the dough to a 1/2 inch thickness. Cut into doughnut shapes using a doughnut cutter or two round cutters, re-rolling scraps as needed.
04 -
Heat 2 inches of vegetable oil in a deep pan or pot to 350°F. Fry doughnuts in batches for 1 to 2 minutes per side until golden brown. Use a slotted spoon to remove doughnuts and drain on paper towel-lined plate.
05 -
In a medium bowl, whisk together powdered sugar, cocoa powder, milk, and vanilla extract until the glaze is completely smooth. Adjust the milk to reach the desired consistency.
06 -
Dip the tops of slightly cooled doughnuts into the glaze, letting any excess drip off. Arrange glazed doughnuts on a wire rack to set.