Cook the pasta following the instructions on the box. Drain the water and set aside. I like to make the sauce as the pasta cooks, so they finish together and can be combined right away.
Make the sauce:
Over medium heat, melt the butter in a skillet with sides. Add the minced garlic and cook, stirring, until it turns golden, about 1 minute. If using garlic powder, melt the butter, add the powder, and immediately proceed to the next step.
Pour in the cream or half-and-half and milk, stirring constantly. Add the grated Parmesan cheese, salt, pepper, and nutmeg (if using) and combine. Bring the sauce to a light simmer and then reduce the heat to low and continue cooking the Alfredo sauce for about 5 minutes.
Combine:
Add the chopped spinach to the Alfredo sauce and stir. Simmer it for about a minute, then add the pasta to the skillet and use tongs to combine it with the Alfredo sauce. Serve it with additional Parmesan cheese on top.
Notes
Swap the minced garlic clove for ½ teaspoon garlic powder.
You can use fresh, baby, or frozen spinach for this recipe because, since it’s chopped and simmered in the Alfredo, the texture difference disappears completely.