Preheat the oven to 475°F. Grease 2 baking sheets and dust with cornmeal, or place a baking stone in the oven and preheat it for 45 minutes. One at a time, flatten each ball of dough on a lightly floured work surface into a 12-inch round, rolling and stretching the dough as necessary.
Place each round on a prepared baking sheet, or, if using a baking stone, place one round of dough at a time on a baker’s peel, below, dusted with cornmeal. Lift the edges and pinch to form a lip on both rounds. Brush the top of the dough with olive oil.
Using your fingertips to push dents in the dough, and let rest for about 10 minutes. Spread 1/2 cup Marinara sauce in an even layer over both pizzas, leaving a 1/2- inch border all around.
Remove the casings from 12 ounces hot or mild Italian sausages. Brown in a skillet over medium heat, breaking up the lumps of meat, about 5 minutes. Drain the sausage.
Sprinkle pizzas with 1 1/2 cups mozzarella, shredded (6 ounces), cooked sausage, 2 red bell peppers, thinly sliced, and Salt and black pepper to taste.
If baking the pizzas on baking sheets, place one pan on the bottom rack. If using a baking stone, slide the pizza off the peel onto the baking stone. Bake one pizza at a time until the crust is browned and the cheese is golden, about 12 minutes.