• 2 c ketchup
• ½ c Turbinado dark brown sugar
• 1 T onion powder
• 1-½ t celery seeds
• 1-½ t garlic powder
• 1-½ t chili powder
• 1 t black pepper finely ground
• 1 t cumin, ground
• ½ t cayenne powder
• ¼ c white vinegar
• 2 T yellow mustard
• 1 t lemon juice
• 4 T butter
• salt to taste

Combine all ingredients, except the butter and salt. Simmer low and slow for at least ½ hour.

Add the butter and allow to melt and thoroughly mix. Taste and add salt as necessary.

Preparation time: 30 minutes

Source, with a few minor tweaks.