For the sauce: Heat the vegetable oil in a medium saucepot over medium heat. Add the garlic and onions and saute until soft, about 4 minutes. Add the ketchup, pineapple, molasses, vinegar, sugar, mustard, Worcestershire and chipotles. Simmer uncovered, stirring often, until thickened, 15 to 20 minutes. Remove from the heat and blend with an immersion blender until mostly smooth. Reserve.
For the burgers: Preheat the grill top to medium-high to high heat.
Form the ground pork into long and rectangular patties that fit the shape of the bread, keeping in mind that there will be 2 patties per half of bread. Sprinkle the exterior with salt and place on a hot grill top for 3 minutes. Flip and cook another 3 minutes. Turn off the heat and baste generously with the BBQ sauce. Flip and continue cooking for a couple more minutes, continuously flipping and basting the burgers.
For the bread: Place the rack in the middle of the oven and set the oven to broil. Mix the melted butter with the garlic and brush on the cut sides of the bread. Top with the cheese and place under the broiler just until the edges are lightly crisped, about 2 minutes.
For the sandwich build: After your beautiful garlic bread is done, place 2 burgers on each bottom half of bread. Top with some pickles and the top half of the garlic bread. Slice each portion in half, yielding 4 sandwiches. Serve with the remaining BBQ sauce on the side and get ready to impress your family and friends.