Step 1

Heat the milk, sugar, and butter in a small saucepan or microwave-safe container, just until the milk is warm and the butter is melted. If it gets overly hot, let it cool before using. You’ll want it to be only warm to the touch when adding it to your sourdough starter. If it’s too hot, it’ll kill your natural yeast, and your donuts won’t rise.

Step 2

Add the milk mixture, the sourdough starter, salt, 2 eggs, and 2 cups of flour to the bowl of your stand mixer.

Step 3

Mix with the dough hook on low speed until the mixture forms a very wet dough, and then mix on medium-low speed to knead very well for 4 to 5 minutes.

Step 4

Let the dough rest for 10 minutes in the bowl with the mixer turned off.

Step 5

After 10 minutes have passed, add a little more flour to the mixture, about 1/3 cup, and let the machine knead the mixture for another 4 to 5 minutes.

Step 6

Turn the very soft dough out onto a lightly floured surface. Knead by hand until the dough is no longer sticky, but is still very tender, adding a little flour, as needed, as you knead. You may add up to another 1/3 cup of flour. Form the dough into a smooth ball.

Step 7

Lightly grease the mixing bowl, and return the dough to the bowl.

Step 8

Cover the dough with a damp kitchen towel, and let it rise for 3 to 6 hours at room temperature.

Step 9

Gently remove the dough from the bowl onto a lightly floured work surface.

Step 10

Roll dough so that it’s ¾- to ½-inch thick, adding a bit of flour as needed to prevent it from sticking.

Step 11

Using a donut cutter or 3-inch and a ¾-inch circle cutters, cut out your donuts and donut holes.

Step 12

Place the cut-out donuts on a baking sheet that is sprayed with cooking spray (you’ll need 2 baking sheets), so that they are at least 1 inch apart.

Step 13

Re-roll any remaining dough, and repeat until you’ve cut all of the dough into donuts.

Step 14

Cover the baking sheets with damp kitchen towels, and let them rest in a warm spot for 1 to 3 hours; they should be slightly puffy when ready.

Step 15

Preheat oil in a large, heavy-bottomed pan or Dutch oven over medium to medium-high heat.

Step 16

While the oil is heating up, make your glaze by melting the butter in a medium bowl. Add the vanilla and stir to combine. Add the powdered sugar and stir to form a thick paste. Thin out the paste with milk, one tablespoon at a time, until the mixture is about as thick as school glue. It’s ok if it’s a little on the thick side; the hot donuts will melt it, and it will coat them well.

Step 17

To fry the donuts, when the oil reaches 350 to 375 degrees F. (use a thermometer), carefully add the donuts to the hot oil, and fry until golden-brown, about 1 1/2 minutes per side. The donut holes will only take about 30 seconds per side.

Step 18

Use a slotted spoon to remove the donuts from the hot oil, and place them on a paper towel-lined baking sheet to remove extra grease.

Step 19

Let them cool slightly. Dip the hot donuts in the glaze (I like to flip on both sides so it’s fully covered), and enjoy right away.