In a 6-quart slow cooker, combine the uncooked pasta along with milks, butter, cheeses, salt and pepper.
Stir well, making sure macaroni is submerged in the liquid as much as possible.
Cover and cook on low heat for approximately 1 ½ - 3 hours, stirring every 30 minutes, until the pasta is cooked through and the sauce is thickened.
Sauce will continue to thicken after lid is removed and as the macaroni sits.
Notes
*For best results, grate your own cheese. Shredded cheese contains an anti-caking agent which can make the macaroni and cheese gritty instead of creamy. *Cook on low heat as the pasta will get gummy when cooked on high.