How to Make Cake Donuts with Chocolate Glaze

• In a bowl, combine the pastry flour, cocoa powder, baking powder, kosher salt, and espresso powder. Mix until evenly combined, then set aside to let the flavors mingle.
• In a stand mixer, beat the granulated sugar and room temperature unsalted butter together until the mixture is light and fluffy, about 2 minutes.
• Beat the egg yolks into the butter-sugar mixture until the volume increases.
• Add the sour cream, alternating with the dry mixture. Blend until just combined.
• Transfer the dough to a covered bowl dusted with flour. Refrigerate for about 60 minutes.
• Roll out the chilled dough to a thickness of ½ inch. Use ring cutters to cut the donuts.
• Let the cut donuts chill for an additional 30 minutes before frying.
• Heat canola oil in a deep fryer or a large pot to 350°F (175°C). Fry the donuts in batches for about 30 seconds per side.
• Allow the donuts to cool slightly before dipping each one in the rich chocolate glaze.