Bring a large pot of salted water to a boil and cook the pasta according to package directions until al dente, about 8-10 minutes. Drain and set aside.

In a large skillet, heat olive oil over medium heat. Add chopped onion and sauté for 2-3 minutes until translucent.

Add sliced mushrooms to the skillet and sauté for 3-4 minutes until browned and tender.

Add fresh spinach to the skillet and cook for 2 minutes until wilted, seasoning with salt and pepper. Remove from heat.

Add minced garlic to the skillet and sauté for 30 seconds until fragrant. Pour in vegetable broth and deglaze the pan.

Stir in cream and Parmesan cheese until smooth. Add chili pepper flakes and Italian seasoning, cooking for 2-3 minutes until it thickens.

Return cooked pasta, mushrooms, onion, and spinach to the skillet. Toss gently to coat pasta in the sauce, cooking for 2 minutes.

Serve hot and garnish with additional Parmesan and red pepper flakes, if desired.