Boil a large pot of salted water on high heat. Add spaghetti and cook until al dente, about 8-10 minutes. Reserve 1 cup of pasta water, drain, and keep warm.

In a skillet, heat 1 tablespoon of olive oil over medium-high heat. Add button and oyster mushrooms, sauté for 5-7 minutes until golden brown.

Reduce heat to low, add another tablespoon of olive oil. Stir in garlic and cook for 1-2 minutes until fragrant. Add chili flakes and reserved pasta water; simmer for 2-3 minutes.

Add the drained spaghetti to the skillet and toss to coat with the sauce. Add more pasta water if needed for a silky texture.

Remove from heat, stir in chopped parsley, and serve hot topped with grated Parmesan cheese.