cook mac and cheese according to directions on box, then spread evenly in a 9 x 9 pan and refrigerate overnight or until cold and set

preheat oven 350F/spray cookie sheet lightly with cooking spray

in a small bowl whisk egg and milk together

in a second bowl combine flour, garlic and onion powders, and salt & pepper

cut cold mac and cheese into 1" x 1" squares

form a square into a ball, roll in flour mixture, then into egg mixture, and then into the breadcrumbs repeat for all mac & cheese

bake 30 min or until desired crustyness is achieved