Heat a smoker to 250°F. Line a rimmed baking sheet with foil or use a grill-safe meatloaf pan.
In a large bowl, gently mix the ground beef, panko, egg, onion, corn, black beans, cilantro, cumin, chili powder, salt, and black pepper. Stop mixing as soon as everything is evenly combined so the meatloaf stays tender.
Shape the mixture into a compact loaf about 8 inches long and place it on the prepared baking sheet or in the meatloaf pan.
In a small bowl, stir together the BBQ sauce, adobo sauce, and apple cider vinegar. Brush about half of the glaze over the top and sides of the loaf.
Place the meatloaf in the smoker and cook until the center reaches 160°F, about 2 to 2 1/2 hours. Brush with the remaining glaze during the last 20 minutes of cooking.
Remove the meatloaf from the smoker and let it rest for 10 minutes before slicing. This helps the slices hold together around the corn and beans.