1Bring a large pot of lightly salted water to a boil. Cook elbow macaroni in the boiling water, stirring occasionally until cooked through but firm to the bite, 8 minutes. Drain and return pasta to pot. Stir butter and milk into macaroni until sauce is smooth.
2Mix croutons and mozzarella cheese into macaroni and cheese until cheese is melted.
1 (7.25 ounce) package macaroni and cheese mix
1/4 cup butter
1/4 cup milk, or more to taste
1 cup crushed garlic and cheese croutons
1/2 cup shredded mozzarella cheese, or more to taste