Mix pizza dough ingredients in a stand mixer for about 20 seconds
Place dough in a bowl to proof
Sauté diced onion and minced garlic until soft
Add tomato sauce, tomato paste, sugar, oregano, basil, and salt to the sautéed mixture
Cover and simmer sauce until reduced
Preheat oven to 425°F
Pour ¼ cup oil into a cast iron skillet
Stretch dough and press it into the skillet with your fingers, edge to edge
Layer half of the pizza sauce over the dough
Add Italian sausage and pepperoni slices
Top with mozzarella cheese
Add more pepperoni slices on top
Place cast iron skillet on a preheated pizza stone
Bake until crust is crispy and cheese is melted
Wait 5 minutes before removing from skillet
Cut into slices and serve
