"This homemade pizza crust uses sourdough starter as a substitute for some of the flour and water. To use the crusts, top frozen crust with pizza sauce, cheese, and toppings. Bake on a pizza pan or stone at 425 degrees F (220 degrees C) until browned, 10 to 12 minutes."
Combine flour, sourdough starter, water, oil, sugar, milk powder, yeast, and salt in a large bowl. Mix by hand until flour is incorporated. Transfer to the bowl of a stand mixer fitted with a dough hook. Knead dough for 6 minutes; allow to rest for 6 minutes. Repeat 3 times.
Transfer dough to an oiled pan; cover with plastic wrap and let rise until doubled, about 1 hour.
Preheat oven to 425 degrees F (220 degrees C).
Separate dough into 6 equal rounds; let rest 10 minutes. Roll out each portion to desired crust size.
Bake in the preheated oven for 5 to 6 minutes. Cool on a rack; freeze in resealable plastic bags separated by parchment paper.