Step 1

Melt the butter and heat the olive oil in a large skillet over medium heat. Drop in the crushed garlic cloves and let sizzle to infuse the oil, 5 to 7 minutes. Remove the pan from the heat.

Step 2

Bring a large pot of well-salted water to a boil. Cook the pasta just shy of the time specified on the package. Reserve 1/2 cup of the pasta water.

Step 3

Drain the spaghetti and dump it into the skillet with the garlic butter. Return the skillet to medium-high heat.

Step 4

Sprinkle in the Parmesan cheese, add some of the reserved pasta water, and cook, stirring continually, until the sauce is smooth and lightly thickened, 3 to 5 minutes. Remove the garlic cloves, if desired.

Step 5

Stir in the parsley, season with salt and pepper, and serve with the Parmesan on the side.