Whisk together the soy sauce, honey, onion, garlic, ginger and crushed red pepper
Place the chicken thighs and your marinade into a large ziplock baggie and marinate for 2 hours to overnight.
Turn the bag halfway through so that all the thighs get equal drenching time.
Place the thighs skin side up in a baking dish that leaves just a bit of room, but not too much, between each chicken thigh. Pour the marinade over the thighs.
Bake at 350°F for 30 – 40 minutes.
Rachel Note - make sure that if you're using boneless, skinless thighs that you check the temperature at about 20 minutes - you don't want to overcook.