Preheat oven to 375ºF
Heat olive oil in large skillet
Pound chicken breasts to an even thickness and season with cumin, chili powder, paprika, garlic powder, salt, and pepper
Transfer to skillet and cook for 2 minutes per side or until just browned
Spread about 1/2 cup salsa on bottom of a baking dish
Arrange browned chicken breasts on top of salsa and add remaining salsa over the chicken breasts
Bake uncovered for 30 minutes or until chicken is done. Use a thermometer to check for doneness (internal temperature 165ºF)
If cheese is desired, remove from oven and sprinkle with cheese, then bake for 3 more minutes or until cheese is melted.
Remove from oven and let stand 5 minutes prior to serving.