Preheat oven to 350°F. Melt butter in a large skillet over medium-high heat. Add the onion and bell pepper; stir frequently until the vegetables are tender, about 5 minutes.
Stir in the beans, hot dogs, brown sugar, mustard, Worcestershire sauce, and garlic powder.
Transfer mixture to a 2-quart baking dish.
Bake, uncovered, for 30 minutes, stirring halfway through. Taste and season with salt and pepper. Garnish with chopped fresh herbs or sliced green onions, if desired.
Serve as a side dish at a cookout or picnic, or offer as a main course with a side of cornbread, rice, or biscuits.