Southern BBQ Sauce

1/4 cup molasses
1 cup ketchup
1/2 cup brown sugar
4 teaspoons liquid smoke
1/2 teaspoon onion salt
1/2 cup vinegar
2 tablespoons vinegar
1/2 teaspoon dry mustard
1/2 teaspoon garlic powder

Combine all ingredients in a sauce pan and simmer on low heat for 30 minutes.