Preheat oven to 400°F. Line a baking sheet with foil and place a wire rack on top.
Gently mix beef, 2 tbsp barbecue sauce, salt, and pepper. Form into four 3½-inch wide, ½-inch thick patties.
Lay two bacon slices in a cross, place a patty in the center, top with pineapple, fold bacon over, and secure with toothpicks. Repeat for all.
Place on the rack and bake for 15 minutes. Brush with remaining BBQ sauce and bake 10–15 more minutes, until internal temp hits 160°F.
Toast buns in a skillet or oven until lightly golden.
Let burgers rest 5 minutes. Remove toothpicks, add to buns with desired toppings, and serve hot.