Cook pasta according to package instructions in a large pot of salted water. Reserve 1 cup pasta water. Drain pasta.

Bring a large pan with 1 ½ tablespoon olive oil and 2 tablespoons butter to medium high heat. Once butter is melted, add shrimp, salt and pepper. Stir occasionally, cooking until pink, about 3 minutes. Remove shrimp from heat, setting aside on a plate.

Set the same large pan to medium heat. Add jarred sauce to heat or make homemade sauce with the following: add ¼ cup butter, stirring around the skillet until coated and melted. Add garlic and cook until fragrant, not burnt, about 30 seconds.

Add heavy cream, garlic powder, salt, nutmeg, and black pepper. Bring heat to medium high, stirring together until well mixed. Bring to a simmer, then reduce heat to medium.

Gradually stir in Parmesan, cooking until well mixed and thickened, about 3-6 (took me 3 minutes). Stir in shrimp. If needed, stir in reserved pasta water to reach desired consistency. Add pasta to sauce, tossing to combine. Serve in bowls topped with parsley, black pepper, and parmesan.