Preheat Blackstone to high heat.
In a small bowl mix together the rub ingredients and set aside.
Place the chicken breast on a cutting board and pat them dry with a paper towel.
Melt 3 Tablespoons of the butter in a bowl. Using the basting brush, brush the melted butter on the chicken breast and then sprinkle the Blackened Rub on the chicken breast. Flip the chicken breast over and repeat on the other side.
Once Blackstone is preheated, melt the remaining 3 Tablespoons of butter on the cooking surface.
Place the chicken breast on the Blackstone in the melted butter..
Once there is a good char on the chicken breast, about 4-5 minutes, flip it over to cook the other side. Cook for another 4-5 minutes.
Turn the heat down to medium then slide the chicken breast together and cover with a dome and cook until internal temp of 165 degrees Fahrenheit. Will take another 5-6 minutes depending on how thick your chicken breasts are.
Pull off the grill, rest for a few minutes, and plate with your favorite side dishes!