Searing the chicken boosts and seals in the Southwestern flavor.
Mix ancho chili pepper, cumin, sea salt, black pepper, cinnamon and oregano with 2 teaspoons of the oil in large bowl. Rub on chicken to evenly coat. Refrigerate 30 minutes
Preheat oven to 350°F. Heat remaining 2 tablespoons oil in large skillet on medium-high heat. Add chicken; sear 1 minute per side. Transfer chicken to baking dish (or leave in the pan if it is oven-proof)
Bake 20 minutes or until chicken is cooked through