Combine the ketchup, brown sugar, vinegar, molasses, Worcestershire sauce (if desired), mustard, garlic, pimentón, black pepper, and cayenne pepper in a medium saucepan.
Cook over low heat, stirring occasionally, for 30 minutes.
Serve warm, at room temperature, or chilled.
(Store leftover barbecue sauce in an airtight container in the refrigerator for up to a few weeks.)
