While bringing salted water to a boil, cook the spaghetti according to package instructions until al dente, about 8-10 minutes. Reserve 1/4 cup pasta water before draining.

In a skillet, heat olive oil over medium-low heat. Sauté minced garlic for about 2 minutes until fragrant, ensuring it doesn't brown.

Stir in chilli flakes for 30 seconds, then add the shrimp. Cook for 3-4 minutes, tossing occasionally until shrimp are pink and opaque.

Pour the reserved pasta water into the pan, increase heat to medium, and let simmer for 2 minutes to meld flavors.

Add the drained spaghetti to the skillet, toss well with the sauce and stir in parsley and grated Parmesan before serving.