Combine the coffee ground, cocoa powder, paprika, chili powder, salt, granulated garlic and onion powder in a medium bowl and set aside.
Coat both sides of the steak with your coffee-cocoa rub, transfer to a plate and cover. Refrigerate for a least an hour or up to 4 hours. Remove from fridge 30 minutes before cooking to let come to room temperature.
Using a cast iron skillet or flat grill pan, rub a thin layer of olive oil on the pan with a paper towel and then preheat over medium heat.
Gently place the steak in the pan. Sear for 4-5 minutes, flip and cook an additional 4-5 minutes for medium-rare or continue cooking to reach the desired doneness.
Remove the steak and transfer to a plate, cover with aluminum foil and let rest for 5-8 minutes.