Mix sugar and cornstarch with a little milk, set aside. Scald remaining milk add to cornstarch mixture and cook until a little thick. take out small amount of milk mixture and add to egg yolks to temper. Add yolk mixture to remaining cornstarch milk mixture and cook until thick. Add butter and pour half of mixture into a prebaked pie shell
Mix graham cracker crumbs,sugar, cinnamon, salt and melted butter until combined. Pour over first layer of cream mixture. Top with remaining cream mixture. Top with merignue made with remaining egg whites and place in oven until top is light brown. Cool before cutting.