Combine sauce ingredients in a small bowl. Cover and chill.
PREPARE THE PORK:
Cut the pork in half lengthwise; cut crosswise into 2½-inch chunks. Combine the apple cider vinegar and the remaining pork ingredients in a medium saucepan; bring to a boil. Add the pork to pan. Cover, reduce heat, and simmer 1 hour or until tender. Remove the pork from cooking liquid; shred with 2 forks. Place the pork in a serving dish; pour the cooking liquid over the pork.
PREPARE THE BISCUITS:
Preheat oven to 425°F. Whisk together the flour, baking powder, and salt in a large bowl. In a separate bowl, combine the potato, sugar, butter and milk; stir well. Pour over the dry ingredients; stir until a soft dough forms (the dough will feel sticky). Turn the dough out onto a floured surface; knead lightly 5 to 6 times. Roll the dough into a 10-inch circle; cut 24 biscuits with a floured 2-inch biscuit cutter. You'll need to cut and then re-roll scraps and cut again. Place biscuits on a baking sheet coated with cooking spray. Bake for 12 minutes or until lightly browned. Remove the biscuits from the pan; cool on a wire rack.
ASSEMBLE THE SANDWICHES:
Place pork and a dollop of the white barbecue sauce in between two biscuits. Serving size is 2 biscuits, ¼ cup pork and 2½ teaspoons barbecue sauce.