1. Boil a large pot of salted water and cook the penne until al dente. Drain and reserve 1/2 cup pasta water.

2. In a large skillet, cook ground beef and sausage over medium heat until browned. Drain and set aside.

3. In the same skillet, reduce heat and melt butter. Stir in garlic and cook for 1-2 minutes until fragrant.

4. Pour in heavy cream and bring to a simmer. Let it thicken for 3-5 minutes, then stir in Parmesan cheese.

5. Return cooked meat to the skillet. Add spinach and stir until wilted.

6. Toss in cooked penne, add a splash of pasta water if needed. Season with salt, pepper, and red pepper flakes.

7. Serve hot with extra Parmesan and a pinch of red pepper if desired.