Chicago Style Deep Dish Pizza

Ingredients

• 3 1/4 cups (16 1/4 oz.) all-purpose flour
• 1/2 cup (2 3/4 oz.) yellow cornmeal
• 1 1/2 teaspoons fine salt
• 2 teaspoons sugar
• 2 1/4 teaspoons instant or rapid-rise yeast
• 1 1/4 cups water (10 oz.), room temperature
• 3 tablespoons unsalted butter , melted, plus 4 tablespoons, softened
• 1 teaspoon plus 4 tablespoons olive oil
• 2 tablespoons unsalted butter
• 1/4 cup grated onion, from 1 medium onion (see note below)
• 1/4 teaspoon dried oregano
• 3 garlic cloves, minced (about 2 teaspoons)
• 1 (28-oz) can crushed tomatoes
• 1/4 teaspoon sugar
• 2 tablespoons fresh basil leaves, coarsely chopped
• 1 tablespoon extra-virgin olive oil
• Salt, to taste
• Black pepper, to taste
• 1 pound whole-milk mozzarella cheese, shredded by handc(about 4 cups) (see note below)
• 1/2 ounce grated Parmesan cheese (about 1/4 cup)
• Hot or mild Italian sausage, casings removed (optional)