In a medium saucepan, add ketchup, white vinegar, molasses, Worcestershire sauce, prepared mustard, and lemon juice. Whisk together until smooth. Stir in the brown sugar, smoked paprika, garlic powder, onion powder, cayenne pepper, Tabasco sauce, black pepper, chilli powder, and salt to taste. Mix well.

Place the saucepan over medium heat. Bring the mixture to a gentle simmer, stirring occasionally. Once simmering, add the butter in chunks, stirring until fully melted and incorporated into the sauce.

Let the sauce simmer for 10-15 minutes, stirring frequently to prevent sticking or burning. The sauce should thicken to a rich, smooth consistency. Remove from heat and let cool slightly. Transfer to an airtight container or jar.