Trim fat from steaks. In a small bowl combine ancho chile pepper, cocoa powder, salt, and black pepper. Brush steaks with oil. Sprinkle chile mixture evenly over steaks; rub in with your fingers.
For a charcoal grill, arrange medium-hot coals around a drip pan. Test for medium heat above the pan. Place steaks on grill rack over drip pan. Cover and grill to desired doneness, turning once halfway through grilling. Allow 25 to 30 minutes for medium-rare (145 degrees F) or 30 to 35 minutes for medium (160 degrees F). (For a gas gill, preheat grill. Reduce heat to medium. Adjust for indirect cooking. Place steaks on grill rack over the burner that is turned off. Grill as directed.)
Cut steaks into serving-size pieces. Serve with papaya butter.
Grilled Papaya Butter
Peel and seed half of a small papaya (reserve remaining papaya for another use); cut into 1/4-inch slices. Lightly brush slices with olive oil. For a charcoal grill, grill papaya on the rack of an uncovered grill directly over medium coals for 5 minutes, turning once halfway through grilling. (For a gas grill, preheat grill. Reduce heat to medium. Place papaya on grill rack over heat. Cover and grill as above.) In a food processor combine grilled papaya and butter. Cover and process with several on-off pulses until papaya is finely chopped. Spoon mixture onto a sheet of plastic wrap. Shape into an 8-inch roll. Wrap and chill about 2 hours or until firm.