Preheat a smoker to 250°F. Line a small rimmed baking sheet with parchment paper.
In a large bowl, combine the ground turkey, egg, breadcrumbs, diced onion, garlic powder, smoked paprika, salt, and black pepper. Mix gently until just combined.
Fold in the smoked cheddar cubes, distributing them through the mixture without overworking it. Shape the mixture into a compact loaf on the prepared baking sheet.
In a small bowl, stir together the BBQ sauce, maple syrup, brown sugar, and apple cider vinegar until the sugar is dissolved.
Place the meatloaf in the smoker and cook until the center reaches 150°F, about 1½ to 2 hours depending on the loaf’s shape and the smoker. Brush the top and sides with about half of the glaze.
Continue smoking until the center reaches 165°F, brushing on the remaining glaze during the final 10 minutes. Check the temperature in the center without touching a pocket of cheddar.
Remove the meatloaf from the smoker and let it rest for 10 minutes before slicing. Serve with any glaze left on the baking sheet.