1. In a large saucepan, melt margarine over medium-high heat. Add onion and cook until softened, about five minutes. Add garlic and cook for 30 seconds.
2. Add ketchup, chili sauce, Dr. Pepper, vinegar, Worcestershire sauce, brown sugar, molasses, onion powder, smoked paprika, sriracha, salt and pepper. Bring to a gentle boil, then turn down heat and simmer for 13 minutes.
3. Use an immersion blender to puree until smooth. Add mini franks to sauce and cook for another 20-30 minutes over low heat. Serve warm with sauce.