<human>:  How to make macaroni and cheese casserole?
<bot>: To make macaroni and cheese casserole, start by preheating your oven to 350°F. Then, cook the macaroni according to the instructions on the package. Next, melt butter in a saucepan and add flour, stirring occasionally. Gradually stir in milk, and cook until the mixture is thick. Add salt, pepper, garlic powder, and shredded cheese to the saucepan, stirring until the cheese melts. Add the cooked macaroni to a greased baking dish and pour the cheese sauce over top. Bake for 25-30 minutes until golden brown and bubbly. Enjoy!