Make the dough: Mix flour, yeast, sugar, salt, and powdered milk (if using). Add warm water and oil. Knead 5 minutes until smooth. Cover and rise 45–60 minutes until puffy.
Make the sauce: Stir together tomato paste, tomato sauce, sugar, garlic powder, onion powder, oregano, basil, salt, and pepper. Set aside.
Cook the beef: Brown ground beef in a skillet over medium-high. Drain grease. Season with Italian seasoning, salt, and pepper.
Prep the pan: Preheat oven to 425°F. Grease a 13×18 sheet pan generously with oil. Add cornmeal if using.
Press the dough: Press dough evenly into the pan, reaching the corners. Rest 5 minutes if it shrinks, then press again.
Par-bake: Bake 7–9 minutes until crust is set. Remove from oven.
Assemble: Spread sauce over crust. Add ground beef. Top with mozzarella (and cheddar if using).
Bake: Bake 10–14 minutes until cheese is melted and bubbling and edges are golden. Broil 1–2 minutes if desired.
Rest + slice: Rest 10 minutes, then cut into squares and serve.