This mega creamy Million Dollar Macaroni and Cheese Casserole is the only macaroni cheese recipe you will ever want to make! Make this mac for guests or family and they will love you forever! The homemade sauce itself is rich and crazy creamy and the casserole is stuffed with a hidden layer of provolone cheese and sour cream that melts when baked for a ridiculous amount of velvety creamy, cheesy goodness. A million dollar worthy goodness.