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

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

Add 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 chicken broth and bring to a simmer. Let it cook for another 2 minutes.

Add the cooked spaghetti to the skillet and toss to combine. Stir in the remaining 2 tablespoons of butter and chopped parsley. Adjust seasoning if necessary.

Serve immediately, garnished with additional parsley if desired.