Place lime juice, cilantro, and chicken breasts in a Ziploc bag or bowl. Make sure the chicken breasts are covered in the mixture. Let sit for 30 minutes.

While the chicken is marinating, make the rub. In a small bowl, combine the lime zest, garlic, chili powder, cumin, paprika, cinnamon, sugar, salt, and black pepper.

Remove the chicken breasts from the bag and discard the bag with juices. Place the chicken on a plate and cover breasts generously with the rub mixture.

Brush clean grill lightly with oil or spray with nonstick cooking spray. Preheat grill to medium-high heat. Grill chicken breasts until chicken is cooked through, about 5 minutes per side. Remove from the grill and garnish with cilantro, if using. Serve warm.