Preheat the oven to 350 degrees. Spray an 11 x 7 pan with cooking spray and set aside.
Cook the pasta according to the package directions and keep warm.
Cook the sausage in a large skillet until brown. Remove from the skillet and drain over paper towels.
Using a small amount of the sausage fat, saute the onion, green pepper, garlic, and red pepper for 5 minutes. Stir in the pumpkin and oregano. Add in the salt. Bring to a boil and simmer for 5 minutes.
Stir in the milk and sausage and simmer until the sauce thickens. Remove from heat and add past and parsley. Pour into the baking pan.
Top with mozzarella cheese and Parmesan cheese. Bake for 20 minutes or until the cheese is bubbly and golden brown.