1 lb sweet hot Italian sausage- ground
1 medium onion, chopped
3 cloves garlic, minced
2 26oz jars marinara sauce
6 Tbsp bottled basil pesto
1 lb penne pasta
1/2 lb mozzarella cheese
1 Cup Parmesan cheese
1 bag (6 oz) spinach (frozen, thawed, works fine)
In large non-stick skillet, cook sausage on medium-high heat, breaking up meat, until meat no longer is pink, 5 minutes. Add onion, stirring constantly until onion is softened, about 5 minutes. Add garlic, cook 1 minute. Add marinara sauce, simmer over medium heat 10 minutes. Stir in pesto. Set aside.
Cook penne according to package directions
Heat oven to 375. Coat 13×9 dish with non-stick cooking spray. Spread thin layer of sauce over bottom of dish.
In large bowl, combine cooked penne, remaining sauce, cheese, 3/4 C Parmesan and the spinach. Spoon into baking dish. Sprinkle the remaining Parmesan over the top.
Bake at 375 for 30 minutes
Source: my mother-in-law