Preheat the oven to 400°F and line a baking sheet with parchment paper.
In a large bowl, combine the ground beef, breadcrumbs, egg, onion, 1/4 cup BBQ sauce, salt, and pepper. Mix until just combined.
Divide the mixture into 8 equal portions and shape each into a small patty about 3 inches wide. Place the patties on the prepared baking sheet.
Brush the tops of the patties with additional BBQ sauce.
Bake for 15 to 18 minutes until the internal temperature reaches 160°F.
While the patties cook, stir together the coleslaw mix, mayonnaise, apple cider vinegar, and sugar in a medium bowl until evenly coated.
Lightly toast the slider buns if desired. Place one patty on each bottom bun, add a spoonful of creamy slaw, and finish with the top bun.