Step 1

Preheat the oven to 425 degrees fahrenheit and spray a 9x13 baking dish with cooking spray.

Step 2

Heat a pan on medium heat and add the olive oil and sausage. Cook the sausage until pale (about 5 minutes) while constantly breaking it up as it cooks.

Step 3

Add and mix together the rigatoni, water, marinara, spinach, cooked sausage, and salt and pepper in the baking dish. Top with the mozzarella cheese and cover with tin foil and bake it on the middle rack for 30 minutes. Remove the tin foil and bake for another 10 minutes, or until the cheese is slightly golden.