Sausage and Pepper Mini Deep-Dish Pizzas

INGREDIENTS

• 1 package (2 1/4 tsp.) active dry yeast
• 3/4 cup warm water (105° to 110°F)
• 1 tsp. sugar
• 1/3 cup vegetable oil
• 2 1/2 cups all-purpose flour, plus more as needed
• 1 tsp. salt
• 3 1/2 Tbs. olive oil
• 2 red or green bell peppers, seeded and thinly sliced
• Salt and freshly ground pepper, to taste
• 1/2 lb. mild Italian sausage, casings removed
• 4 slices provolone cheese
• 1/2 lb. mozzarella cheese, grated
• 1/4 cup grated Parmigiano-Reggiano cheese
• 2 cups tomato pizza sauce