Boil the macaroni in water for five minutes. Drain.
In a medium saucepan on low heat, melt the butter. Once the butter is almost all melted, slowly and gradually add the shredded cheese, stirring as you add. Continue to stir until the cheese melts.
In ceramic bowl of a 4-quart crock pot, combine melted cheese mixture, soup, sour cream, milk salt, and pepper. Stir in the macaroni.
Place the lid on the crock pot, and cook on low for 2 ½ -3 hours, stirring occasionally.
Crock Pot Mac & Cheese can be made ahead, simply refrigerate the cooked pasta separately from the cheese sauce, and stir together when you're ready to turn on the crock pot.Adapted from Repeat Crafter Me