Prep: Spray a 9x12 (or similar) baking dish with cooking spray. Preheat oven to 350°F.
Cook Sausage: In a large skillet over medium heat, heat oil. When oil is hot, add Italian sausage and cook, breaking up the meat as it cooks (about 3-4 minutes). Drain any grease, if necessary. Hint: During the last 2 minutes of cooking, use a potato masher to break up the meat nice and fine!
Add: When sausage is browned, add pasta sauce, Italian seasoning, garlic powder, onion powder and sugar. Mix well to combine and simmer for 3-4 minutes. Stir in heavy cream.
Start to Assemble: Spread about 1 1/2 cups of the sauce evenly over the bottom of your casserole dish. Then, add tortellini in an even layer.
Layer: Add half the cheese on top of the tortellini. Then layer on the rest of the sauce and finally, top with the remaining cheese. Make sure all of the tortellini is covered with the sauce/cheese.
Bake: Cover with aluminum foil, then bake in a preheated oven for 25-30 minutes until bubbly and the dish is hot throughout. Optional: Broil for the last 2-3 minutes to get the cheese golden brown.
Rest: Remove pan from the oven and let the dish rest for a couple of minutes. If you like, top with Parmesan cheese, chili flakes and fresh parsley or basil. Serve right away.