Bring a large pot of salted water to a boil. Add the green beans and cook for 4 minutes. Drain the green beans and set aside.
In a medium saucepan, melt the butter over medium heat. Whisk in the flour and cook for 1 minute. Slowly whisk in the milk and garlic powder. Cook until the sauce is thick and bubbling, about 5 minutes.
Remove from heat and stir in the cheese until melted. Add the green beans and bacon and stir until combined. Season with salt and pepper to taste.
Transfer the green bean mixture to a greased 9x13 inch baking dish. Bake for 15 minutes, or until bubbling and golden brown.
Interesting Facts
Green beans are a good source of vitamins A and C.
Bacon adds a smoky flavor and crunchy texture to the green bean bake.
This dish can be prepared ahead of time and refrigerated overnight before baking.