Preheat oven to 350 degrees

Spray donut molds with nonstick cooking spray - I prefer the silicone version since the donuts come out easier and don't stick

In a large bowl, whisk together the flour, cocoa powder, nutmeg, salt, sugar, brown sugar, and baking powder

In a separate bowl, whisk together buttermilk, yogurt, oil, and eggs until smooth and fully combined. Whisk in melted chocolate as best as you can; there will still be clumps, but that's OK since they will create delicious pockets of chocolate in the baked donut.

Pour the wet ingredients to the dry ingredients, stirring until just combined.

Spoon or pipe the donut batter mixture into the greased donut pan, filling each about 3/4 full. Don't overfill or your batter will spill over the top.

Place in the oven and bake donuts for 10-12 minutes or until a toothpick inserted comes out clean.

Let the donuts cool in the pan for 5 minutes, remove from the molds, and place onto a wire rack for 5 minutes, then place on a sheet of parchment paper

GLAZE

In a small bowl, whisk together the powdered sugar and milk until smooth

Gently dunk the top of each donut into the glaze and allow the excess to drip off before placing on the parchment paper

Immediately add the sprinkles evenly over the top of each donut while the glaze is wet.