In small bowl, whisk bourbon, maple syrup, Dijon mustard, olive oil, soy sauce, garlic, Italian seasoning, and salt and pepper together.
Place the chicken thighs in a container, or freezer bag, and pour marinade over chicken.
Place container in fridge for at least 2 hours, or overnight.
Preheat oven to 350 degrees.
Spray a cast iron skillet grill with nonstick cooking spray and heat over medium.
Season the chicken thighs with salt and pepper. Add them to the skillet, skin-side-down, and cook for about 7 minutes.
Then, flip the chicken thighs and cook for another 5-7 minutes.
Transfer the chicken thighs to a baking sheet lined with foil and nonstick cooking spray.
Continue cooking for 15-20 minutes, or until the meat is cooked through.
Allow the chicken to rest 5 minutes before serving.