Special equipment: meat thermometer
For the rub: Combine the sugar, cocoa, coffee, pepper, salt and chile powder in a bowl and stir to combine.
For the steak: Preheat a grill. Drizzle the steak with olive oil. Sprinkle with half of the rub and then massage it into the meat. Flip over and repeat on the other side. Grill the steak until a meat thermometer reaches 130 to 140 degrees F for medium rare, 6 to 7 minutes per side. If you like medium, cook the meat until it reaches 140 to 150 degrees F. Rest the meat for 10 minutes before slicing and serving.