Created by KittenCal on October 28, 2011
Step 1: Preheat oven to 375 degrees F (oven rack set to lowest position) then grease a 13 x 9-inch baking dish.
Step 2: Spread the cooked penne pasta mixture into bottom of the baking dish.
Step 3: Drizzle the prepared alfredo sauce over the top; set aside.
Step 4: In a skillet cook the sausage meat with onion until browned (about 10-12 minutes) drain fat then sprinkle over the alfredo sauce.
Step 5: Top with 3/4 cup Parmesan cheese then mushrooms, then sprinkle with 2 cups mozzarella cheese.
Step 6: Bake for about 20-25 minutes or until hot.