Combine remaining egg whites and yolks in a medium mixing bowl. Add 1/2 cup sugar to egg mixture; beat until well blended. Stir in scalded milk, coffee, 1 teaspoon vanilla, and 1/4 cup plus 1 tablespoon macaroon crumbs.
Pour mixture into a lightly greased 1-quart casserole. Place in an 8-inch square baking pan; add warm water to a depth of 1 inch. Bake at 300° for 1 hour and 10 minutes or until a knife inserted halfway between center and edge comes out clean. Remove casserole from water immediately; cool to room temperature. Chill thoroughly.
Beat reserved egg white (at room temperature) until foamy. Gradually add 1 1/2 tablespoons sugar, beating until stiff peaks form. Fold in whipped cream and 1/4 teaspoon vanilla. Spread over top of custard. Sprinkle additional macaroon crumbs over top. Spoon custard into individual serving bowls; serve immediately.