In a large saucepan, heat olive oil over medium heat. Add chopped onions and cook until softened, about 3-4 minutes.
Stir in baked beans, ketchup, mustard, brown sugar, and black pepper. Mix until well combined.
Add sliced hot dogs to the pan. Stir and cook until the mixture is hot and bubbly, about 10-12 minutes.
Serve warm with your favorite sides like cornbread or a green salad.