In a large bowl, combine cream cheese, sour cream, cottage cheese, half of the mozzarella, Italian seasoning, garlic powder, onion powder, and a pinch of salt and pepper. Stir until smooth and well blended.
Spray your slow cooker with non-stick spray.
Spread a thin layer of marinara sauce on the bottom.
Add half of the uncooked tortellini in an even layer.
Spoon half of the creamy cheese mixture over the tortellini and spread gently.
Add half of the browned sausage (or ground beef) on top, then pour half of the remaining marinara sauce over it.
Repeat the layers: tortellini, creamy cheese mix, sausage, marinara.
Sprinkle the remaining mozzarella and all of the Parmesan cheese evenly over the top.
Cover and cook on low for 4–5 hours, or until the tortellini are tender and everything is hot and bubbly.
Garnish with chopped parsley and basil before serving.