Spinach & Cheese Rigatoni Bake

16-oz. pkg. rigatoni pasta, uncooked
3 T. olive oil, divided
10-oz. pkg. frozen spinach, thawed and drained
2 c. ricotta cheese
5 T. grated Parmesan cheese, divided
3/4 t. salt
1/4 t. pepper
Optional: 1/2 t. nutmeg
1-1/2 c. shredded fontina cheese, divided
Garnish: additional grated Parmesan cheese

Cook rigatoni according to package directions. Drain; toss with one tablespoon oil and place in a greased 13"x9" baking pan. Combine spinach, ricotta and 3 tablespoons Parmesan in a food processor and purée. Add salt, pepper and nutmeg, if desired. Stir in half of fontina; combine spinach mixture with rigatoni. Top with remaining fontina and Parmesan; drizzle with remaining oil. Cover and bake at 450 degrees for 15 to 20 minutes, until golden and heated through. Serve with additional Parmesan cheese for sprinkling.