- Preheat oven to 400 °F.
- In a medium saucepan, combine baked beans, onion, brown sugar and mustard.
- Stir until well mixed.
- Cook over medium heat, stirring occasionally, until baked beans are hot, 10 to 15 minutes.
- Meanwhile, rinse frankfurters and blot dry with paper towels.
- Spear 3 hot dogs together by pushing a toothpick horizontally through upper third of franks.
- Repeat with remaining wieners.
- Place a 6-inch-tall 1½ to 2 quart baking dish about 4½ inches in diameter (such as a bean pot) on an oven-proof serving platter.
- Lean frankfurters, skewered ends up, around outside edge of bean pot.
- Tie a piece of kitchen string around center of franks to secure them in a circle.
- Remove toothpicks.
- Transfer hot baked beans from saucepan to pot in center of franks and place platter and all in oven.
- Bake until weiners are golden brown and baked beans are bubbly, about 25 minutes.
- To serve, spoon baked beans directly form pot and use tongs to remove frankfurters.