Step 1

For the donuts: In the bowl of a stand mixer fitted with a dough hook, whisk together the all-purpose flour, potato flour, granulated sugar, yeast and salt. Add the milk, eggs and vanilla extract and mix with the dough hook to combine. With the mixer running, add the butter, 1 tablespoon at a time, until fully incorporated into the dough. Use a rubber spatula to scrape down the bottom and sides of the bowl, as needed. Mix on medium speed, dusting with a light sprinkling of flour as needed, until the dough pulls away from the sides of the bowl and is completely smooth and slightly sticky, about 10 minutes. Stretch the dough into a ball. Lightly oil a clean, large mixing bowl and place the dough in the bowl, turning it around and upside down to fully coat. Cover with plastic wrap or a clean, dry towel. Let the dough rise at room temperature until it’s doubled in size, 1 1/2 hours.

Step 2

Turn the risen dough onto a lightly floured surface and roll out to 1/2-inch thick. Cut into donuts with a 3-inch donut cutter, then transfer to a parchment-lined baking sheet that has been dusted with some flour. (You can form the dough scraps into a ball, allow to rest for 30 to 45 minutes, then repeat the process of rolling it out and cutting additional donuts.) Cover with plastic and let proof in a warm place until slightly puffed and increased in volume, 45 minutes.

Step 3

Prepare a heavy-bottomed pot with oil for frying. When the oil reaches 350 degrees F, fry the donuts 3 or 4 at a time, flipping every 30 seconds (a pair of chopsticks works well for flipping these), until puffed up to double their size and golden brown, a total of 3 to 4 minutes. Remove to a rack. Allow the oil to come back to temperature before frying another batch.

Step 4

Meanwhile, prepare the glaze: Combine the powdered sugar, vanilla, salt, and 3 tablespoons of the milk in a mixing bowl. Whisk until smooth, adding more milk if needed to achieve a thick but drizzle-able consistency. Add a few drops of desired food coloring. Place in a piping bag until ready to pipe onto donuts.

Step 5

Pipe the glaze on top of the cooled donuts. Add sprinkles before they dry. These are the best super-fresh, but they can be stored in an airtight container on the counter.