1. Bring a large pot of salted water to a boil. Cook linguine until al dente. Drain and set aside, reserving 1/2 cup of pasta water.

2. In a large skillet over medium-high heat, brown ground beef and Italian sausage until no longer pink. Drain excess fat.

3. Reduce heat to medium. Add butter and minced garlic to the pan. Sauté until fragrant, about 1 minute.

4. Pour in heavy cream, stir to combine, and simmer for 2–3 minutes.

5. Add mozzarella and Parmesan cheeses, stirring until melted and creamy.

6. Stir in spinach and cook until wilted. Season with salt, pepper, and optional red pepper flakes.

7. Add cooked linguine to the skillet and toss to coat. Use reserved pasta water to loosen the sauce if needed.

8. Serve hot with extra cheese on top if desired.