Combine all the dry spices in a small bowl: onion powder, garlic powder, cayenne, dried oregano, dried thyme, salt, paprika, and brown sugar. Mix thoroughly to ensure the spices are evenly distributed. I like to use smoked paprika specifically because it adds that deep, charred flavor that makes blackened chicken taste authentic—it's worth seeking out.

Place the chicken breasts on a cutting board and pound them to an even 3/4-inch thickness using the flat side of a meat mallet—this ensures uniform cooking across the entire breast. Once pounded evenly, coat both sides of each chicken breast with about 1 tablespoon of vegetable oil total (roughly 1/3 tablespoon per breast on each side). The oil helps the spice rub adhere to the chicken and creates that signature blackened crust.

Generously coat both sides of each oiled chicken breast with the spice blend from Step 1, pressing gently so the spices adhere to the oil. Make sure to cover the edges as well—this creates an even blackened crust all around. Set the seasoned chicken aside on a clean plate.

Heat your Blackstone griddle to 400°F, then add the remaining 1-2 tablespoons of vegetable oil (Crisco works perfectly here because of its high smoke point). Once the oil is shimmering and the griddle is fully preheated, carefully place the seasoned chicken breasts onto the hot surface. Let them sear undisturbed for 4-6 minutes—resist the urge to move them around, as this allows the spices to caramelize and create that beautiful blackened crust. I've found that letting them sit longer on the first side helps develop deeper color and flavor.

Flip each chicken breast and cook for an additional 5-6 minutes on the second side until the internal temperature reaches 165°F when checked with a meat thermometer in the thickest part of the breast. Transfer the cooked chicken to a clean plate and let it rest for 10 minutes before serving—this resting period allows the juices to redistribute throughout the meat, keeping it tender and moist rather than dry.