Combine olive oil, salt, cumin, chili powder, garlic powder and white vinegar in a bowl and mix well.
Place chicken in a shallow dish. Pour marinade over the top. Toss chicken to coat completely. Cover and refrigerate for 6 - 8 hours or overnight.
Preheat oven to 450 degrees.
Spread sliced jalapenos and sliced onions on the bottom of a baking dish. Lay marinated chicken over the top. Pour any remaining marinade over the top. Pour chicken broth over the top.
Bake chicken in oven for 15 minutes at 450 degrees. Reduce heat to 350 and bake for 20 more minutes. Baste chicken pieces every 10 minutes. After 20 minutes, turn on the broil and broil for 10 minutes to crisp the skin. Transfer to a serving platter. Serve.