Preheat your oven to 450 degrees Fahrenheit.
Add the brown sugar, honey, orange juice, mustard, vinegar, and spices to a small saucepan and heat over medium-high heat. Simmer the sauce for 2 to 3 minutes while stirring with a wooden spoon until the sugar has dissolved and the sauce thickens slightly. The sauce should coat the back of a spoon. Set the sauce aside.
Heat two tablespoons of olive oil in a 10-inch cast-iron skillet or medium oven-proof skillet over medium-high heat. Season the chicken thighs with salt and cracked pepper on both sides and transfer them to the skillet, skin side down.
Cook the chicken thighs for 7-8 minutes, or until the skin is browned and crispy, then flip the chicken and cook for an additional 5-6 minutes. Pour the brown sugar glaze over the chicken in the skillet, being sure to coat all of the chicken, and transfer the skillet to the preheated oven.
Cook the chicken in the preheated oven for 8-10 minutes, or until the chicken is cooked through (an instant read thermometer inserted into the chicken should read 165 to 170 degrees Fahrenheit), basting the chicken with glaze halfway through.
Turn on the oven broiler and cook the chicken for an additional 2 to 3 minutes to crisp the skin and caramelize the exterior. Allow the chicken to rest for 10 minutes. Enjoy!