This is a BBQ sauce I whipped up and I think it's pretty good.
Many home cooks fail by cranking the burner too high, causing the massive quantity of brown sugar and molasses to caramelize and turn bitter before the raw onions and garlic soften. Sauté the chopped onions in butter over medium-low heat until translucent before introducing the acidic components, which halts further softening.
Because sugar-heavy liquids retain immense heat and thicken further upon cooling, determining doneness requires watching how the liquid behaves on the spoon. Pull a wooden spatula through the simmering pot; if the parting trail holds its shape for two full seconds before filling back in, the sauce has reached the ideal coating consistency.
Vinegar cuts through the heavy sweetness of four cups of catsup and two cups of dark brown sugar, but boiling time alters that ratio through evaporation. Simmer the mixture uncovered for at least 20 minutes to meld the capsaicin from the cayenne and habanero powders with the underlying tomato base, yielding a harmonious profile rather than sharp heat.