Preheat oven to 375F.

Heat a large skillet over medium high heat. Add olive oil and the beef, sprinkling with salt and garlic powder. Break into small pieces and cook until browned, about 5 minutes. Drain any excess fat if desired. Remove from heat and set aside.

Spray a high-sided 9?13 baking dish with olive oil spray. Add the tortellini, half the marinara (about 1 ? cups), and ? cup water, tossing so that the tortellini is equally covered in sauce, then spread into an even layer.

Sprinkle over the spinach in a layer, then carefully add the cooked beef in another layer.

Evenly spread over the remaining marinara (about 1 ? cups), then sprinkle evenly with cheese.

Cover tightly with foil. Bake for 30-40 minutes covered or until browned, bubbling, and the tortellini is cooked to your liking. Optionally, uncover and bake or broil for 5 minutes until browned on top.