Preheat oven to 325°
Mix the flour, cocoa, baking powder and salt. Set aside.
Using a hand mixer - combine the sugar, egg, Greek yogurt, milk, and butter.
Add the dry ingredients and mix until combined.
Generously spray donut pan with non stick.
Split the batter evenly between the six donut molds.
Bake at 325° for 12-15 minutes.
Remove from oven and allow to cool in pan for 2-3 minutes.
Transfer donuts to cooling rack.