In a large bowl, beat the egg whites until soft peaks form. Fold the egg whites gently (use a rubber spatula) into the marscapone mixture. Line the bottom of a souffle dish with half of the lady fingers. If you don't have a souffle dish, use any 2 quart straight sided dish. Carefully spread with half of the marscapone mixture. Sift 2 tablespoons of cocoa over this. Repeat the layers and top with the remaining cocoa powder. Cover with Saran wrap and refrigerate for at least two hours.