Boil spaghetti in salted water until al dente. Reserve 1/2 cup pasta water and drain.

In a large skillet, heat olive oil over medium heat. Add garlic and chilli flakes. Sauté for 1-2 minutes until fragrant.

Add prawns to the skillet. Season with salt and pepper. Cook 2-3 minutes per side until pink and cooked through.

Add butter and let it melt into the skillet.

Toss in the cooked pasta and a splash of reserved pasta water. Stir to coat everything in the sauce.

Squeeze in lemon juice, add parsley, and toss again. Serve hot with extra chilli flakes if desired.