Preheat the oven to 400°F and line a baking sheet with parchment paper or lightly grease a baking dish.

Pat chicken breasts dry with paper towels.

Place each breast between two sheets of plastic wrap and pound with a meat mallet or rolling pin until an even 3/4-inch thickness.

In a small bowl, whisk together olive oil, garlic powder, onion powder, paprika, oregano, salt, and black pepper.

If using the marinade, combine the optional marinade ingredients in another bowl. Place breasts in the marinade and refrigerate for 30 minutes to 2 hours. Remove from marinade and pat dry before applying the dry rub.

Rub the seasoning mixture over both sides of each breast so each piece is evenly coated.

Arrange the breasts in a single layer on the prepared baking sheet.

Bake for 18 to 22 minutes. Start checking at 18 minutes with an instant-read thermometer inserted into the thickest part; the safe internal temperature is 165°F.

Remove from oven and let rest for 5 minutes before slicing.

Garnish with lemon slices and chopped parsley or cilantro, then serve warm.