Preheat your oven to 425 degrees. Spray a 9x13 pan with non stick cooking spray. If you want to be fancy, line the bottom of the pan with orange slices (optional).
In a small saucepan, combine the orange juice, orange zest, rice vinegar, soy sauce, brown sugar, ginger, and red pepper flakes. Bring to a boil, then reduce heat to medium-low and simmer for about 5 minutes.
Place your chicken thighs skin-side up in the prepared baking dish. Pour half of the glaze over the chicken thighs.
Cook in the oven for about 30 minutes. Take the remaining glaze and pour it over the chicken.
Cook for an additional 15-20 minutes. The skin will get nice and crisp and browned.