Preheat oven to 350º and spray a donut pan with cooking spray. Set aside.
In a medium size mixing bowl, add both sugars and melted butter and whisk until fully combined.
Add in egg, yogurt, milk, and vanilla extract and mix.
Add in your dry ingredients - flour, cocoa powder, baking soda, and salt. Switch to a rubber spatula or spoon and fully mix. Batter will be very thick, almost like a frosting texture.
Fill the donut spaces 3/4 full, taking care not to overfill. *Tip: to fill the donut pan easier, place the batter in a piping bag or a gallon size storage bag and cut the corner tip off and pipe the batter into the donut spaces.
Bake for approximately 8 minutes or until a toothpick inserted comes out clean.
Remove from oven and let donuts cool in pan for a few minutes before transferring to a wire rack to cool completely.
While the donuts are cooling make your chocolate ganache.
Heat heavy cream in a microwave safe bowl for approximately 60 seconds or until boiling. Pour in the chocolate chips and give a quick stir to ensure all of the chips are covered, then leave the ganache to sit undisturbed for 2-3 minutes.
Once the 2-3 minutes are up, whisk until a smooth, chocolatey ganache has formed. If the ganache has any lumps, heat another 15 seconds and whisk until smooth. Repeat if needed.
Dip the tops of the donuts in the ganache and transfer back to the cooling rack to fully set before enjoying.
Store donuts in an airtight container at room temperature for up to two days or in the fridge for up to a week.