In a large skillet, brown the Italian sausage over medium-high heat. Drain off any excess grease.
Transfer the browned sausage to your slow cooker.
Add the crushed tomatoes, diced tomatoes (with their juice), chicken broth, heavy cream, Italian seasoning, and garlic powder to the slow cooker. Stir to combine.
Cover and cook on low for 3-4 hours, or on high for 1.5-2 hours, until the sauce is heated through and flavors have melded.
Add the refrigerated tortellini to the slow cooker and stir gently. Cook for an additional 20-30 minutes, or until the tortellini is tender and cooked through.
Stir in the shredded mozzarella and grated Parmesan cheese until melted and combined.
Season with salt and pepper to taste. Serve hot.
Notes
This crockpot tortellini recipe is incredibly versatile. You can add spinach in the last 30 minutes of cooking, or top with fresh basil before serving.