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 2 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 (if using). Cook until the shrimp turn pink, about 3-4 minutes. Remove shrimp from skillet and set aside.

In the same skillet, add the chicken broth and bring to a simmer. Stir in the heavy cream and remaining butter, cooking until the sauce thickens slightly.

Return the shrimp to the skillet and add the cooked spaghetti. Toss to combine and heat through.

Remove from heat and stir in chopped parsley.

Serve the garlic butter shrimp pasta warm, garnished with additional parsley if desired.