Preheat oven to 350 degrees F (180 degrees C)
Lightly grease a 3 quart baking dish with cooking spray
Spread about ½ cup sauce on the bottom of the dish and arrange half of the ravioli in a single layer over the sauce
Top with cooked sausage, spinach, and sundried tomatoes
Pour 1 ½ cups of alfredo sauce over the spinach mixture
Sprinkle with half of the mozzarella and Parmesan cheese and top with the remaining ravioli in a single layer
Pour over remaining sauce and top with remaining mozzarella and Parmesan cheeses
Cover and bake for about 1 hour, uncovering during the last 15 minutes, until golden brown around the edges and bubbly
Let stand 10 minutes before serving
