Preheat oven to 350℉.
In a large bowl, mix together all-purpose flour (1 cup), granulated sugar (½ cup), unsweetened cocoa powder (¼ cup), baking soda (½ teaspoon), and mini semi-sweet chocolate chips (½ cup). Set the bowl aside.
In a separate large bowl, whisk together vanilla extract (¾ teaspoon), egg (1 large), sour cream (¼ cup), and milk (¾ cup).
Stir the wet ingredients into the dry ingredients and stir until just combined.
Melt the ½ cup semi-sweet chocolate chips in the microwave (on half power) for 1-2 minutes (or until melted). Pour melted chocolate into batter and mix until combined.
Spray the donut pan with non-stick cooking spray and scoop 3 tablespoons of batter in each donut cavity (or until they are half full). If batter gets in center, use a mini spatula to clear that area (you will want this clear so your donut has the traditional hole in the center). TIP: for easy filling, use a cookie scoop or spoon batter into a gallon-sized bag, snip off the corner, and pipe it in.
Bake at 350℉ for 8-10 minutes, or until toothpick comes out clean (mine took exactly 10 minutes to bake, but watch your oven carefully to prevent from overbaking).
Once baked, let the donuts cool IN the pan on a wire rack for 5-10 minutes before removing. Top with ganache and sprinkles.