Remove the silver membrane from the back of the ribs by sliding a butter knife under it and pulling it off with a paper towel; this helps them get extra tender. Use a towel as a visual grip and pull the membrane away in one sheet where possible.

In a small bowl, mix garlic powder, onion powder, smoked paprika, black pepper, salt, and cayenne pepper. Rub the spice mixture all over both sides of the ribs, pressing lightly so it sticks evenly.

In a medium bowl, whisk BBQ sauce, crushed pineapple with its juice, brown sugar, soy sauce, apple cider vinegar, minced garlic, and Worcestershire sauce until the sugar dissolves and the sauce looks glossy. Stop whisking when no sugar granules remain.

Pour about 1/3 of the pineapple BBQ sauce into the bottom of the crockpot. Tilt the crockpot slightly if needed so the sauce spreads into an even layer.

Place the ribs inside, standing them upright along the edges if needed (cut the rack in half for a better fit). Arrange them so they sit snugly and can heat through evenly.

Pour the remaining sauce over and around the ribs, coating them well. Make sure the top surfaces and sides are covered so the glaze clings during cooking.

Cover and cook on LOW for 7–8 hours (or HIGH for 4–5 hours) until fall-off-the-bone tender and pulls away easily. Look for meat shrinking slightly from the bones and sauce thickening around the edges.

Carefully remove the ribs and place them on a foil-lined baking sheet, then brush with extra sauce from the crockpot. Coat the tops with a thin, even layer so the glaze caramelizes rather than puddles.

Broil at 425°F for 5–7 minutes until the sauce caramelizes and gets slightly charred. Watch closely in the last 2 minutes for dark amber spots without burning.

Garnish with chopped fresh cilantro and serve with extra pineapple BBQ sauce on the side. Add pineapple rings if using for a bright, sweet finish.