Preheat a cast iron pan over high heat. Brush each side of the steak with oil and then season each side liberally with salt and pepper. Rub 2 tablespoons of the coffee rub onto 1 side of each steak. Cook the steak, rub side down until golden brown, about 3 to 4 minutes. Flip the steak over, cook for 2 minutes and then transfer to a baking sheet and cook in the oven to medium-rare doneness, about 8 to 10 minutes. Remove and let rest 5 minutes before slicing.