Preheat your oven to 350°F (175°C).
Wash and trim the green beans, then blanch them in boiling water for 5 minutes.
In a large bowl, mix cream of mushroom soup, milk, garlic powder, onion powder, salt, and pepper.
Add the blanched green beans to the mixture and stir to combine.
Fold in half of the French fried onions and half of the cheddar cheese.
Transfer the mixture to a greased 9x13 inch baking dish.
Sprinkle the remaining cheddar cheese on top.
Add the breadcrumbs if using, for extra crunch.
Bake in the preheated oven for 25 minutes until bubbly.
Remove from oven and top with the remaining French fried onions, then bake for an additional 5 minutes.