Prepare the spice rub by mixing onion powder, garlic powder, paprika, chili powder, cayenne pepper, salt, and black pepper in a bowl. Pat the chicken thighs dry and coat them with the rub.

In a saucepan, combine diced peaches and sugar over medium heat, cooking until the peaches soften. Add barbecue sauce and bourbon, and simmer for an additional 5 minutes.

Blend the peach mixture until smooth and set aside to cool.

Preheat the grill to medium-high heat and brush the grates with oil.

Grill the chicken thighs for 3-5 minutes on each side until cooked through and grill marks appear.

Brush glaze on one side of the chicken, cook for another minute, then flip and coat the other side.

Grill remaining peaches for 1-2 minutes on each side, brushing cut sides with barbecue sauce.

Serve the chicken with grilled peaches and drizzle with extra glaze.