In a large pot, bring salted water to a boil. Add spaghetti and cook according to package instructions until al dente. Drain and set aside.

In a skillet over medium heat, melt 4 tablespoons of butter. Add minced garlic and sauté for about 1 minute until fragrant.

Add the shrimp to the skillet, season with salt, pepper, and red pepper flakes. Cook for 2-3 minutes on each side until shrimp are pink and opaque.

Pour in the chicken broth and remaining butter, stirring to combine. Add the cooked pasta and parsley, tossing to coat evenly.

Serve immediately, garnished with additional parsley if desired.