MERINGUE CRACKER CRUST: Beat egg whites until stiff. Combine sugar and mace; add 1 T at a time to egg whites, beating well after each addition. Add vanilla. Combine crushed crackers, baking powder and nuts. Fold into egg white mixture. Spoon into buttered 25 cm pie plate, pushing mixture to conform to shape of pie plate.. Bake at 350 deg F for 30 minutes. Cool. (This crust is excellent for chiffon or ice cream pie.) STRAWBERRY FILLING: Combine crushed strawberries, sugar and lemon peel. Soften gelatin in cold water in pan. Heat gently to melt the gelatin. Add to crushed berry mixture. Chill until mixture begins to thicken. Spread half the mixture over the bottom of cooled crust. Add enough whole berries, stem end down and close together, to fill pie. Carefully spoon remaining crushed berry mixture around whole berries. Chill until firm. Serve with whipped cream, if desired.