Preheat the oven to 375°F. Lightly grease 8 cups of a standard muffin pan.
In a large bowl, whisk the egg with 2 tablespoons of the barbecue sauce. Stir in the breadcrumbs, corn, cheddar, onion, garlic powder, salt, and black pepper.
Add the ground beef. Mix gently with your hands or a fork just until everything is combined. Avoid packing the mixture tightly so the muffins stay tender.
Divide the mixture evenly among the 8 greased muffin cups. Shape each portion loosely, then spread the remaining 2 tablespoons of barbecue sauce over the tops.
Bake until the muffins are cooked through and reach 160°F in the center, about 20 to 25 minutes. Let them rest in the pan for 5 minutes, then remove and serve.