In small bowl, combine the light brown sugar, paprika, cumin, salt, garlic powder, thyme, black pepper and cayenne pepper. Rub the seasoning into the chicken, making sure it's entirely coated.
Heat 1 tablespoon olive oil over medium-high heat in large skillet. Add chicken to skillet and cook for 4 minutes per side or until blackened. Remove from skillet and serve immediately.
Notes
Multiply the spice mixture by 4X and then save the rest in a jar for later use.
You can adjust the spice level by adding or removing cayenne pepper in ¼ teaspoon increments.
Make sure the skillet is hot before adding the chicken. It should be just beginning to smoke.
Let the chicken rest for 5 minutes, covering with foil, before serving so the juices stay inside.