Mystery Pie
["3 egg whites", "1 c. sugar", "1 tsp. baking powder", "12 soda crackers", "1 c. chopped walnuts", "1/2 tsp. vanilla"]
["Beat egg whites until stiff.", "Crush crackers into crumbs. Fold crumbs and remaining ingredients into beaten egg whites. Bake for 30 minutes at 325\u00b0.", "Be sure to grease pie plate well. After it cools, cover with whipped cream."]
["egg whites", "sugar", "baking powder", "crackers", "walnuts", "vanilla"]