Preheat your oven to 350°F (175°C).
Steam the broccoli florets until just tender, about 5 minutes.
In a large bowl, mix together cream of mushroom soup, mayonnaise, and shredded cheddar cheese.
Stir in the steamed broccoli until well coated.
Add salt, pepper, and garlic powder to taste.
Transfer the mixture to a greased baking dish.
In a separate bowl, combine breadcrumbs and melted butter.
Sprinkle the breadcrumb mixture over the broccoli mixture evenly.
Bake in the preheated oven for 25-30 minutes until bubbly and golden brown.
Let it cool for a few minutes before serving.