Pat the chicken thighs dry very thoroughly using paper towels. This crucial step helps the skin crisp up during cooking. In a small bowl, combine all the ingredients for the Southwest Spice Rub: chili powder, brown sugar, smoked paprika, cumin, oregano, garlic powder, onion powder, and cayenne pepper (if using).

Season the chicken thighs liberally on all sides with kosher salt and black pepper, then generously massage the prepared spice rub onto the chicken, ensuring it adheres well to both the skin and the meat underneath.

In a separate small saucepan, combine the honey, minced chipotle peppers in adobo, fresh lime juice, apple cider vinegar, and salt. Heat the mixture over medium heat, stirring occasionally, until the mixture is simmering gently and the honey has fully dissolved (about 3 to 4 minutes).

Remove the glaze from the heat and set aside. Reserve about 2 tablespoons of the fresh, warm glaze for brushing on the finished chicken; do not mix this reserved portion back into the main pot used for basting.

Preheat your grill to a medium-high heat (about 400°F). Lightly oil the grill grates to prevent sticking. Set up the grill to have a direct heat zone and an indirect heat zone (necessary for slow cooking chicken thighs).

Place the chicken thighs skin-side down over the direct, medium-high heat. Cook undisturbed for 5 to 7 minutes until the skin is deeply golden brown and crispy. Watch carefully for flare-ups; if they occur, move the chicken to the indirect heat zone immediately.

Flip the chicken thighs so they are skin-side up and move them to the indirect heat zone. Cover the grill and continue cooking for approximately 15 to 20 minutes, or until the internal temperature reaches about 160°F.

Begin basting the chicken generously with the main batch of the Chipotle-Honey Glaze using a pastry brush. Close the lid and allow the glaze to caramelize slightly (about 3-4 minutes). Baste once more and cook until the internal temperature of the chicken registers 170°F to 175°F at the thickest part of the thigh (avoiding the bone).

Remove the chicken thighs from the grill and place them on a clean cutting board or serving platter. Brush the warm chicken one last time with the reserved fresh glaze. Tent the chicken loosely with aluminum foil and allow it to rest for 5 to 10 minutes before serving. This ensures maximum juiciness.