Barbecued Little Smokies

Source: The New Beta Sigma Phi Holiday Cookbook

1 cup barbecue sauce
1 cup catsup
12 large marshmallows
1/2 cup packed brown sugar
1 (16 ounce) package Little Smokies smoked cocktail wieners
1/4 cup finely chopped onion (optional)

Mix first four ingredients in fondue pot. Heat until marshmallows melt, stirring frequently. Add wieners and onion. Simmer for 30 minutes.