Fillings: Combine egg yolks and condensed milk in a double boiler.
Cook until thick or of spreading consistency, stirring constantly.
Add the butter and vanilla; blend well and cool.
Meringue: Preheat oven to 300 °F.
Beat the egg whites and cream of tartar till soft peaks are formed.
Add sugar gradually and continue beating until stiff but not dry. Add orange extract.
Spread meringue on a heavily greased and wax-lined jelly roll pan.
Bake for 20 minutes or until light brown.
Turn onto a well-buttered piece of waxed paper and immediately spread filling.
Roll as for jelly roll. Good for 6 to 8 persons.