If you don't have three pans, you can bake these in batches -- just be sure to thoroughly wash and dry the pans in between.
Vanilla Confectioners'-Sugar Glaze + Pepitas
Whisk together 3 cups confectioners' sugar, 1/4 teaspoon kosher salt, and 1 tablespoon pure vanilla extract. Whisk in 6 to 8 tablespoons whole milk until mixture is smooth and thick, and has the texture of pourable honey. Glaze can be refrigerated in an airtight container up to 3 days; stir until smooth before using. (Makes 1 1/2 cups.)
Skip the pepita sugar and dip the top of each donut in glaze until halfway submerged, turning as needed to evenly coat one side, then place, glaze-side up, on racks and sprinkle with ground pepitas. Let stand until completely set, about 1 hour. Donuts are best served the day they are made but can be stored, unglazed, in an airtight container at room temperature up to 1 day; glaze 1 hour before serving.