These chocolate cake donuts are light and perfectly cakey with an explosion of chocolate flavor! The glaze gives them just a little extra sweetness. Perfection.
In a large bowl, whisk together the flour, cocoa powder and baking powder. Whisk in the kosher salt and espresso powder to distribute. Set aside.
Either line a baking sheet with plastic wrap and then sprinkle the surface of the plastic wrap with all-purpose flour or spray the inside of a large mixing bowl with nonstick spray. Set this aside too.
In the bowl of a stand mixer fitted with the paddle attachment, beat together the granulated sugar and butter on high speed until the butter has completely incorporated. There is too much sugar in proportion to butter in doughnut dough for it to look as “light and fluffy” as cake batter might.
Add the egg yolks and continue to beat on high until the mixture lightens and the volume increases. This will take about 2 minutes. Stop and scrape down the mixture a few times to be sure it is all evenly incorporated.
With the stand mixer on low, gradually add the dry ingredients to the bowl a large spoonful at a time, alternating with spoonfuls of sour cream. Add the next spoonful when you only see a few large streaks of flour left in the bowl. I alternate almost nonstop between the two. Stop the mixer to scrape in the last bit of sour cream. Only mix until the dry ingredients are fully incorporated. You want to do this as quickly as possible so that not too much gluten develops, which will make tunnels in your donuts and also make them tough.
Transfer the dough to the prepared bowl or plastic wrap lined baking sheet. Sprinkle the top of the dough with all-purpose flour and then fold the edges of the plastic over the top to cover it. Refrigerate it for 60 minutes. At this point, the dough can be held in the fridge for up to 2 days.
Portion and cut dough:
Line a half-sheet baking pan with parchment paper and spray the paper with nonstick spray. Set this aside.
Lightly dust a work surface with flour. Turn the dough out onto your floured work surface, floured side down. Lightly dust the top with more flour if you didn’t flour the plastic wrap.
Working quickly to keep the dough cool, roll out the dough to ½ inch thick.
Brush any excess flour from the top of the dough. Use 3-inch and 1 ¼ - inch ring cutters to cut the donuts and holes. You can use a donut cutter, biscuit cutter, cookie cutter, or even the rim of a glass! Lightly tap the cutters in flour before cutting each donut. Brush off any excess flour with a dry pastry brush. Place the donuts and donut holes on the prepared sheet pan.
Cover the sheet pan with plastic wrap, but be sure not to let the plastic touch the top of the donuts. Chill in the refrigerator for at least 30 minutes up to overnight at this step.
Make the glaze:
In a medium bowl, whisk together the milk, powdered sugar and salt. Cover the glaze with plastic wrap directly on the surface to prevent it from getting a skin. You can heat up the glaze over a pot of simmering water on the stove if you want it to be warm when the donuts are ready to be dipped. I typically dip my donuts while they are still very hot, so I don’t need to do this.
Fry the donuts:
Pour oil into a fryer or a Dutch oven, making sure the oil is at least 2 inches deep. Heat your oil to 350°F. Adjust your heat to keep the temperature between 350°- 360°F while frying. You will need a clip-on fry/candy thermometer for this. I heat my oil up to 360°F before adding a batch of donuts, because the cold dough will lower the temperature of the fryer oil.
Gently place 3 donuts in the fryer, while keeping the remaining donuts in the fridge. The number you can fry at once depends on the size of your pot. You want the donuts to have room to move around and space to puff. Once they rise to the surface, cook for 30 seconds and then flip them with a slotted spoon. Fry until they start to puff and split a little, about 80 seconds. Flip it again and then fry for another 80 seconds or until the color is nice and even. I usually test mine with a cake tester. Pull it out of the oil, poke it and then pull the cake tester out. It should not have any streaks of dough or crumbs. Transfer to a wire rack set over a sheet pan or paper towels. Donut holes fry for 30 seconds then flip, then another 60 seconds, then flip, then another 40-60 seconds. They will puff up and be golden brown all over.
Once the donut is just barely cool enough to handle, dip the donut in the glaze and place it back on the wire rack. Dipping a hot donut will give you a nice, even glaze that isn’t too thick or too thin!
You can store your donuts at room temperature in a container with the corner cracked overnight, but they are best consumed the day they are fried…with coffee.
Video
Notes
Presentation - To get a clean glaze coating, dip your donuts while they are still warm!Flavor Tips - The secret to the intense chocolate flavor, without the weight of adding liquid chocolate, is using the best Dutch processed cocoa powder you can lay your hands on. Droste cocoa powder is also darker than a lot of other Dutch processed cocoa powders, which gives my donuts that rich chocolate color AND flavor.Technique - Keep the dough cold. The faster, more gently you work, the more tender the donuts will be! Helpful Tools - In order to fry donuts, you will need a clip/candy thermometer, a spider or slotted spoon, and a fryer or a Dutch oven that can hold at least 2 inches deep of oil. It is also useful to have a baking sheet and a wire cooling rack.Variations - If you want to go in a fruity direction, check out my Strawberry Lemon Cake Donuts, and if you’re feeling festive my Pumpkin Spice Cake Donuts will give you the measurements for your favorite spices. You can also always mix up the glaze!Storage - Old fashioned chocolate cake donuts are best the day they are made but will keep three days at room temperature. I do not recommend refrigerating or freezing fried cake donuts.