Melt your butter in a skillet on your stovetop over medium-high heat

Add in as much of your chicken as will fit in your pan, cooking a few minutes on each side until it is golden, repeat for remaining chicken

Place your onions in the bottom of your crock pot

Put your browned chicken on top of your onions

In a separate bowl, mix together your ketchup, cider vinegar, molasses, Dijon mustard, onion powder, ground cumin, garlic powder and hot sauce

Pour your sauce all over your chicken

Cover and cook on low for 4 hours (your chicken will be tender and the sauce thick when it is done)

Shred your chicken with forks (or a mixer, whichever you prefer) and serve on buns