In a medium bowl, whisk together the balsamic vinegar, water, dried onion, red pepper flakes, garlic, salt, pepper, paprika, rosemary, parsley, chili powder, and oregano.
Place the chicken breasts in a resealable plastic bag and pour the marinade over them. Seal the bag, pressing out excess air, and massage the marinade into the chicken. Refrigerate for at least 30 minutes, or up to 24 hours for maximum flavor.
Preheat your oven to 400°F (200°C). Line a baking sheet with aluminum foil or lightly grease a broiler pan.
Remove the chicken breasts from the marinade and let any excess drip off. Discard the remaining marinade.
Arrange the chicken on the prepared pan in a single layer. Bake for 30-40 minutes, or until the internal temperature reaches 165°F (74°C). The chicken should appear golden brown and smell irresistibly fragrant.
Remove from the oven and let the chicken rest for 5 minutes before slicing and serving. Enjoy!