Melt the butter in a medium saucepan over medium heat. Stir in the onion and garlic and saute for 5 minutes. Add the tomatoes, reduce heat to medium low and simmer for 15 minutes. Then add the ketchup, mustard, brown sugar, honey, cayenne pepper, chili powder and Worcestershire sauce.
Simmer for 60 more minutes, then transfer mixture to a blender or food processor and puree until smooth.
