In a non-reactive saucepan over medium-high heat, whisk together the ketchup, brown sugar, pineapple juice, molasses, tamarind paste, liquid smoke, mustard, garlic powder, onion powder, and chili powder.
Bring the sauce to a low boil; reduce heat to low, cover, and simmer until flavors have blended, about 15 to 20 minutes. Season to taste with apple cider vinegar, salt, pepper, and cayenne pepper.
Notes
Molasses: Substitute 1/4 cup dark corn syrup, honey, or maple syrup, or 3 tablespoons firmly-packed brown sugar (the flavor of the sauce will change).
Tamarind paste: Look for this sour paste in Asian and Indian sections of grocery stores. In a pinch, you can substitute 1 teaspoon brown sugar + 1 teaspoon white vinegar or lime juice. You can also buy it online (Culinary Hill may earn money if you buy through this link).
Liquid smoke: In a pinch, substitute 2 teaspoons smoked paprika (the flavor of the sauce will change).
Cayenne pepper: Add to taste (I like 1/8 teaspoon) or omit entirely.
Yield: One batch makes about 4 cups of sauce.
Make ahead: Cool and refrigerate up to 4 days in advance.
Storage: Store leftovers covered for up to 4 days in the refrigerator.
Freezing: Freeze for up to 3 months. Thaw overnight in the refrigerator.