Preheat your oven to 425°F (218°C). Position rack in the middle position.
Pat chicken breasts dry with paper towels to remove excess moisture for proper browning.
If chicken breasts are uneven in thickness, place between plastic wrap and gently pound to achieve uniform 3/4-inch thickness.
In a small bowl, combine salt, pepper, garlic powder, cumin, and chili powder.
Brush each chicken breast with olive oil on both sides, then apply the seasoning mixture evenly to all surfaces.
Spread 1/3 cup of the salsa evenly across the bottom of a 9x13-inch baking dish.
Arrange seasoned chicken breasts in the baking dish, ensuring they don't overlap.
Spoon remaining salsa over each chicken breast, covering completely.
Place in preheated oven and bake for 15 minutes at 425°F.
Reduce oven temperature to 375°F (190°C) without opening the oven door and continue baking for 10-15 minutes.
Verify doneness with a digital thermometer inserted into the thickest part of the breast; it should read 165°F (74°C).
If using cheese, sprinkle it over the chicken and return to oven for 2-3 minutes until melted.
Remove from oven and let rest for 5 minutes before serving to allow for temperature carryover and moisture redistribution.
Garnish with fresh cilantro and serve immediately.