Cook pasta according to package instructions until al dente. Reserve 1 cup of pasta water before draining.

In a large skillet, heat olive oil over medium heat. Add sliced mushrooms and cook for 5-7 minutes, until softened and golden brown.

Add minced garlic and sauté for 1 minute, then add spinach and cook until wilted.

Pour in heavy cream and stir in Parmesan (if using), salt, and pepper. Let the sauce simmer for 3-5 minutes until slightly thickened.

Add the cooked pasta to the skillet, tossing to combine with the creamy sauce. If needed, add some reserved pasta water to reach the desired sauce consistency.

Serve immediately, topped with extra Parmesan or fresh herbs if desired.