Bring a large pot of salted water to a boil. Add fettuccine and cook according to package instructions until al dente, about 8-10 minutes. Reserve ½ cup pasta water, then drain and set aside.

In a large skillet, heat olive oil over medium heat. Slice chicken sausage into bite-sized pieces and add to the skillet. Sauté for 5-7 minutes until browned and cooked through, then remove from skillet.

In the same skillet, reduce heat to medium-low and melt butter. Add minced garlic and sauté for 1 minute until fragrant.

Pour in heavy cream and allow to simmer for 3-4 minutes until thickened, stirring occasionally.

Gradually stir in Parmesan cheese, mixing continuously until fully melted and creamy. Season with salt and pepper, and adjust thickness with reserved pasta water.

Add the cooked fettuccine and sautéed chicken sausage back into the skillet. Toss gently to coat evenly in the sauce.

Serve onto plates and garnish with chopped parsley and extra Parmesan if desired.