Spray a regular or mini doughnut pan with baking spray. Preheat oven to 375F.

In a small bowl whisk the cocoa powder with the hot water until dissolved. 

Stir in the baking soda and sour cream and set aside. 

In the bowl of an electric stand mixer fitted with the paddle attachment, beat the brown sugar with the oil until combined. 

Add the egg and vanilla and beat until light in color. 

Add the flour, baking powder, and salt and beat on low speed for a few seconds. 

Pour the cocoa mixture into the mixer and mix until smooth and combined. 

Fill piping bag fitted with a small straight tip or a ziptop bag with the corner snipped off with batter. Pipe the batter into the doughnut pan, filling each doughnut 2⁄3 of the way full.

Bake for 8-10 minutes until the doughnuts spring back to the touch. 

Allow to cool slightly and then turn the doughnuts out onto a cooling rack. 

Once cool, finish the dough- nuts with your favorite glaze.