Place the chicken thighs in a shallow bowl or a zip top bag. Set aside.
In a small bowl, whisk together the vinegar, honey, garlic powder, cumin, salt and pepper.
Pour the marinade over the chicken thighs, tossing the chicken to coat on all sides.
Marinade the chicken for 1 hour or up to 4 hours.
Prepare the grill.
Remove the chicken from the marinade and place on the grill over medium high heat.
Cook the chicken for 4-5 minutes and then flip the chicken over. Continue to cook for an additional 4-5 minutes until cooked through and the chicken registers 165˚F on a thermometer.
Transfer the chicken to a platter and cover with foil to keep warm.
Melt the butter in a small saucepan over medium heat and stir in the honey.
Pour the hot honey butter over the chicken and toss to coat.