Boil a large pot of salted water and cook spaghetti according to package directions until al dente.

Reserve 0.25 cup of pasta cooking water before draining the remaining liquid.

Heat olive oil in a large skillet over medium heat.

Sauté minced garlic and red pepper flakes for 60 seconds until fragrant but not browned.

Incorporate fresh baby spinach into the skillet and toss continuously until wilted.

Combine the cooked pasta and reserved pasta water with the spinach and garlic mixture.

Add parmesan cheese, salt, and pepper while tossing vigorously to emulsify the sauce.

Serve immediately while the emulsion is stable.