Baked Rigatoni With Red Peppers and Green Olives

Name: Baked Rigatoni With Red Peppers and Green Olives
Ingredients: 2 Tbsp. extra-virgin olive oil; 1 medium onion, finely chopped; 4 garlic cloves, thinly sliced; 1 (16-oz.) jar roasted red peppers, drained, finely chopped (about 1¾ cups); 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt; Freshly ground black pepper; 1 cup green olives, smashed, pits removed; 2 Tbsp. double-concentrated tomato paste; ¼ tsp. crushed red pepper flakes; 1 (14-oz.) can whole peeled tomatoes; 1 lb. rigatoni, penne, or ziti; Kosher salt; 4 Tbsp. unsalted butter; 2 tsp. finely chopped oregano; 2 oz. Parmesan, finely grated, divided; 1 lb. fresh mozzarella, torn into bite-size pieces, divided; Handful torn basil leaves (for serving)