Combine the sugar, yolks, and butter in the bowl of the Bosch Mixer with the paddle attachment. Set the mixer to high and mix until the color of the mixture lightens and its volume increases, about two minutes. Stop the mixer, add the sour cream, then mix on medium until the mixture becomes smooth, about one to two more minutes.
Sift the dry ingredients into a mixing bowl and stir them together.
Lightly coat the inside of a medium mixing bowl with nonstick spray, line the bowl with plastic wrap, and press the wrap into the inside of the bowl. Coat the exposed plastic wrap inside the bowl with another layer of nonstick spray. Set the bowl aside.
With the Bosch Mixer set to low, add the dry ingredients to the wet ones, one large spoonful at a time, waiting a few seconds between spoonfuls and stopping the mixer when the dry ingredients are completely incorporated. Transfer the dough to the bowl lined with plastic wrap; spray the top of the dough with the nonstick spray; cover it, placing the ends of the plastic wrap directly on the dough; and put it in the refrigerator for 60 minutes. TIP: At this point, the dough can be held in the fridge for up to a week.
Line a half-sheet pan with parchment paper, coat the paper with nonstick spray, and set it aside.
Lightly dust a work surface with flour. While the dough is still in the bowl, dust the top with flour, then transfer it from the bowl directly onto the floured work surface. Working quickly to keep the dough cool, lightly dust the top of the dough with more flour. (You can always add more if you need it later.) Roll to about a half-inch thick. Brush any excess flour from the surface of the dough. Use a 3 in (75 mm) and a 1 1/4 in (30 mm) ring mold to punch out your doughnuts, dipping the bottoms of the molds in flour before every cut. Use the middles to make doughnut holes!
Transfer the doughnuts to the lined sheet pan and brush any last bits of flour off of them. Cover the pan with plastic wrap, making sure the wrap doesn’t come into contact with the doughnuts and place the pan in the fridge for 30 minutes.
Finish by sprinkling chocolate honey sugar over doughnuts.