8.5 oz Sugar, granulated 3.2 oz Egg yolk, beaten (about 5–6 large) 1.3 oz Butter 13.4 oz Sour cream 1 lb 5.2 oz Pastry flour, or all-purpose 0.53 oz Baking powder 0.42 oz Kosher salt - Nonstick spray, as needed 1 recipe Doughnut Glaze, optional - Oil for frying, we use canola, as needed Combine the sugar, yolks, and butter in the bowl of a stand mixer fitted 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 stand 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. In a large pot over medium heat, bring at least two inches of fry oil to 340 °F / 170 °C. Clip a thermometer to the edge of the pot and monitor the temperature regularly, stirring occasionally to keep the heat even. Set a timer to the stopwatch function. Cooking one at a time until you get the hang of it, place a donut in the fryer. Once it rises to the surface, cook it for 40 seconds, then use a spider strainer or slotted spoon to flip it and fry until the bottom develops a nice, golden-brown color, about 80 seconds. Flip it one more time and fry for another 80 seconds. Transfer to a rack over a metal tray or onto a paper towel-lined plate. TIP: If the dough warms and becomes sticky and difficult to transfer, slide the parchment sheet off the sheet pan and onto a cutting board. Cut the parchment around each donut, then just slide your hand under the parchment and use it to transfer the donut to the fryer. Let the donuts cool for 15 minutes before glazing. If they’re too warm, the glaze will just run right off the sides. If your glaze isn’t nice and viscous, warm it in a bain-marie (or just float its container in some hot water). Dip your donut about three-quarters of the way in, then use a chopstick to pull it out of the glaze and transfer it onto a cooling rack, dry side down. The glaze should run down enough to cover the last quarter of the donut.