Whisk ¼ cup kosher salt and ¼ cup granulated sugar into 2 quarts of cold water to create the brine.

Poke holes all over the chicken breasts with a fork, then pound them to ½-¾ inch thickness inside a zip-top bag.

Place the tenderized chicken breasts into the zip-top bag with the brine. Seal and brine for 30 minutes at room temperature or up to 24 hours in the refrigerator.

Combine 1 tsp salt, ¼ tsp black pepper, ¼ tsp cayenne pepper, 1 tsp garlic powder, 2 tsp smoked paprika, and ½ tsp onion powder in a small bowl to make the seasoning blend.

Remove chicken from brine and pat thoroughly dry with paper towels.

Generously coat the dried chicken breasts with the prepared spice blend on all sides.

Grill the seasoned chicken breasts over medium-high heat for 6-8 minutes per side, or until internal temperature reaches 165°F (74°C) and grill marks are deep golden brown.

Let the chicken rest for 5 minutes before slicing and serving.