For the Sauce:
2 tablespoons unsalted butter
¼ cup grated onion
¼ teaspoon dried oregano
½ teaspoon salt
2 garlic cloves, minced
1 (28-ounce) can crushed tomatoes
¼ teaspoon sugar
2 tablespoons coarsely chopped fresh basil
1 tablespoon olive oil
Freshly ground black pepper
For the Toppings:
1 pound mozzarella cheese, shredded (about 4 cups)
(Pepperoni)
¼ cup grated Parmesan cheese