Combine chicken breasts and bbq sauce in the bowl of your slow cooker. Place lid on top and cook for 3-4 hours on high, or 5 hours on low (you don't want to overcook it, keep an eye on it if you can). Shred chicken with two forks once it is cooked through.
To make Bacon Avocado Dip Mix, combine mix packet with sour cream and mayonnaise in a medium sized bowl. Refrigerate until ready to use.
In a large skillet, melt 1/2 TB butter over medium high heat. Add a tortilla to the pan, and top with a sprinkling of cheese (about 1/4 cup) followed by a scoop of bbq chicken. Spread out evenly, then top with a little diced onion and cilantro (about 1 heaping TB each) and another 1/4 cup of cheese. Top with second tortilla.
When bottom tortilla is golden brown, carefully lift quesadilla with a spatula and add another 1/2 TB butter to the pan. All to melt then flip quesadilla over and cook the other side.
Repeat steps 3-4 to make remaining quesadillas.
Serve with salsa, remaining cilantro, and Bacon Avocado Dip. Enjoy!