Pat chicken dry and season with salt, pepper and garlic powder and place in your slow cooker.
Pour apple cider vinegar, Worcestershire sauce, BBQ sauce, Italian seasoning, chili pepper flakes, and brown sugar in your slow cooker, coating the chicken.
Turn on high and cook for 4 hours, until the chicken is easily shreddable.
Shred chicken with two forks.
Place a slice of the pepper jack cheese on each bottom pretzel bun. Lightly toast/broil the buns until just golden and cheese is melted.
Add chicken to toasted buns and top with fresh jalapeño slices.
Recipe by 5* trending recipes with videos at https://food.theffeed.com/2022/12/08/spicy-slow-cooker-bbq-chicken-sandwich/