Preheat oven to 350°F. Spray a donut tin generously with nonstick baking spray.
In a large bowl, whisk the flour, baking powder, baking soda, cocoa, salt, and sugar together.
1 cup all-purpose flour, ⅓ cup unsweetened cocoa powder, ½ teaspoon baking powder, ½ teaspoon baking soda, ⅛ teaspoon kosher salt, ½ cup granulated sugar
In a medium bowl, mix the egg, yogurt, oil, and vanilla extract together.
1 large egg, ½ cup plain yogurt, ¼ cup canola oil, 1 teaspoon pure vanilla extract
Pour the wet ingredients into the dry and mix until the batter is just smooth.
Transfer the batter into the donut tin using a spoon or piping bag. Fill each well only to a little more than ¾ full.
Bake for 8-10 minutes. Test if the donuts have been baked properly by inserting a toothpick. It should come out clean. Allow the donuts to cool for 5 minutes. Then flip the pans upside down over a wire rack. Repeat as needed until all donuts have been baked.
Using a microwave-safe bowl, heat the chocolate chips, butter, milk, and vanilla extract for 30 seconds, or until melted (depends on microwave setting). Stir until smooth.
½ cup chocolate chips, 2 tablespoons unsalted butter, 1 tablespoon milk, ½ teaspoon pure vanilla extract
Generously frost the donuts with the chocolate glaze and top with sprinkles.
2 tablespoons chocolate sprinkles