Mix. Combine all of the ingredients for the rub in a small bowl. Stir well to combine, using a fork to break up any clumps.
¼ cup dark brown sugar, 1 Tablespoon coarse sea salt, 2 teaspoons black pepper, 2 teaspoons smoked paprika, 2 teaspoons garlic powder, 2 teaspoons onion powder, 1 teaspoon ground mustard powder, ½ teaspoon cayenne pepper