Combine the applesauce, apple cider vinegar, Worcestershire sauce, maple syrup, Dijon mustard, hot sauce, garlic powder, cinnamon, and salt in the base of a crock pot. Whisk together.
Add the chicken into the sauce. Cover with a lid and cook on LOW for 4-5 hours until the chicken is tender enough to be easily shredded.
When the chicken is done, transfer it to a plate and shred with a fork. Set aside.
Add 2-3 tablespoons of the sauce from the slow cooker to a small bowl, then pour the remaining sauce into a medium saucepan and set over high heat. Whisk the cornstarch into the reserved sauce to create a slurry, then stir it into the sauce in the saucepan.
Reduce heat to a simmer and cook for 10-15 minutes, until the sauce has thickened slightly. Remove from heat.
While the chicken cooks, prepare the slaw by using a mandolin or very sharp knife to shred the cabbage into fine, thin pieces.
Slice the apples into long, thin pieces using a mandolin or very sharp knife so it is about the same size as the cabbage. Add the cabbage, apples, and diced jalapeno to a large bowl.
In a medium bowl, whisk the lemon juice, Greek yogurt, apple cider, apple cider vinegar, mustard, honey, salt, pepper, and celery seed together. Pour over the cabbage and apple mixture and toss until everything is well coated.
To assemble the sandwiches, I like to toast the buns for by buttering them lightly and cooking them on a griddle for a few minutes, but it's not totally necessary. Top the bottom bun with shredded chicken, some of the applesauce BBQ sauce, a big scoop of slaw and finish with the top bun!