In a medium, heavy-bottomed saucepan, thoroughly whisk together the ketchup, dark brown sugar, molasses, apple cider vinegar, and Worcestershire sauce until the sugar is completely dissolved.
Whisk in the smoked paprika, garlic powder, onion powder, mustard powder, black pepper, salt, and cayenne pepper until fully incorporated.
Place the saucepan over medium-high heat and bring the mixture to a gentle boil, stirring constantly so the thick tomato base does not scorch the bottom.
Once bubbling, immediately reduce the heat to the lowest setting. Let the sauce simmer gently, uncovered, for 15 to 20 minutes. Stir occasionally. You will notice the texture becoming beautifully thick and glossy, and the color darkening.
Remove the pot from the heat and allow the sauce to cool completely at room temperature, which will thicken it even further. Pour it into a clean jar and store in the refrigerator for up to 2 weeks.