Bring a large pot of salted water to a rolling boil. Add the fettuccine and cook according to package instructions until al dente, about 10-12 minutes. Reserve about a cup of pasta water, then drain.

In a large skillet, heat 2 tablespoons of olive oil over medium heat. Slice chicken sausage into bite-sized pieces and add to the skillet. Sauté for about 5-7 minutes until golden brown. Transfer sausage to a plate.

Reduce heat to low in the same skillet, add 2 tablespoons of butter until melted. Add 2 tablespoons of minced garlic, sauté 30 seconds until fragrant. Pour in 1 cup of heavy cream, let it simmer gently for 2-3 minutes.

Slowly add 1 cup of grated Parmesan cheese to the cream mixture, stirring until melted and creamy, about 2-3 minutes. Season with salt and pepper to taste.

Return the sautéed chicken sausage to the skillet with the sauce and add the cooked fettuccine. Toss gently until evenly coated. Add reserved pasta water if too thick.

Transfer to serving plates, sprinkle with freshly chopped parsley and extra Parmesan cheese. Serve warm.