Pesto and Sausage Baked Ziti

This is from MelsKitchenCafe. It is THE BEST. 

1 lb ziti or penne noodles

1 lb Italian turkey or Chicken sausage, casings removed (I use Italian)

1 medium yellow chopped onion

2 cloves minced garlic

1 (28 oz) can diced tomatoes

1 cup pesto (I use store bought)

9 oz loose baby spinach (about 5 cups)

15 oz ricotta cheese

2 cups shredded mozarella

1 1/2 c grated parmesan

Preheat oven to 375. Grease 9x13 pan and set aside. Bring a large pot of salted water to a boil over high heat. Add pasta and cook until al dente. Drain. While the pasta is boiling, in a large skillet over med heat, add the sausage, onion and garlic and cook until the sausage is cooked through, adding a bit of salt and pepper to taste. White it cooks, break it up into small pieces. Drain grease if any. Add the diced tomatoes, pesto and salt and pepper to taste (about 1/2 tsp salt and 1/4 tsp pepper) to skillet. Simmer for 10-12 minutes. Add the spinach, stirring until it cooks down about 1-2 minutes. In a medium bowl, combine the ricotta cheese, 1 1/2 c mozarella and 1 1/4 c parmesan. Pour drained noodles into 9x13. Dollop the ricotta mixture over the top of noodles. Spread the sauce over the top and sprinkle with remaining cheese (1/2 c mozzarella and 1/4 c parmesan). Bake until heated through and golden, about 20 minutes. Let stand 5 mintues before serving.