Fire up your grill for indirect cooking 350-400 F. You do not want flame directly below the place where you plan on placing the planks
Cut the thighs in half lengthwise. Place a cube of mozzarella in the center and roll the chicken around it.
Wrap a half piece of bacon around the chicken.
Sprinkle the chicken with the rub. Don't be shy with it.
Transfer to the planks, leaving at least 1/2" space between each chicken roll.
Transfer planks to grill and cook for 1 - 1 1/2 hours. As the bacon and chicken begin to render fat you may experience flare-ups. I keep a spray bottle full of fresh water nearby when this happens, being careful to spray down into the grill at the fire and not at the chicken which would rinse off the seasoning.
Meanwhile, place the butter and hot sauce in a small saucepan over medium heat. Bring to a simmer and let simmer for 5 minutes, stirring the help melt the butter.
Once the chicken hits 155 F internal temperature (make sure you measure in the meat, not the cheese!) using an instant-read thermometer, brush heavily with the Buffalo sauce.
Cook another 10-15 minutes or until the chicken is done (at least 165 F).
Brush with any remaining sauce and serve!
Notes
I like to have tons of Buffalo sauce, so I double the ingredients and serve half alongside the chicken for dipping.