Heat the oven to 400°F. Lightly grease 8 cups of a standard muffin pan.
In a large bowl, combine the ground turkey, egg, breadcrumbs, onion, 2 tablespoons of the barbecue sauce, Worcestershire sauce, garlic powder, salt, and black pepper. Mix gently just until combined.
Divide the mixture evenly among the 8 prepared muffin cups. Shape each portion lightly so it fills its cup without packing it tightly.
Bake for 15 minutes. Carefully spoon the remaining barbecue sauce over the tops, then bake for another 5 to 8 minutes, until the centers reach 165°F.
Let the meatloaf muffins rest in the pan for 5 minutes, then lift them out carefully. Place one muffin on each slider bun and top with coleslaw and 2 pickle chips. Serve warm.