Rinse the crabs under cold running water and brush them with a small brush if necessary to remove any dirt on their outer shells. Twist off and discard the apron. Fold back the pointed sides of the top shell to expose the gills; remove the gills on both sides. Using kitchen scissors, cut across the front of the crab about 1/4 inch behind the eyes and mouth and squeeze out the small sac hiding directly behind the mouth. The crabs are now ready to be cooked.

Preheat a grill to medium-high with the lid down.

Brush the crabs with some of the olive oil, and season them with salt and pepper. Place the crabs on the grill, cover it, and cook, turning the crabs every few minutes and basting them with the remaining olive oil until they turn orange and are cooked through, 7 to 9 minutes, depending on their size. Remove from the grill, and serve hot.

6 servings