Tart Lemon Jelly Roll

3 large eggs
1 cup granulated sugar
5 tablespoons water
1 teaspoon vanilla extract
1 cup sifted flour
1 teaspoon baking powder
1/4 teaspoon salt
1/2 cup confectioners' sugar
Clear Lemon Jelly Filling

Grease and flour a 15 1/2 x 10 1/2-inch jelly roll pan. Beat with rotary beater until thick: 3 large eggs. Gradually beat in 1 cup sugar. Beat in all at once water and vanilla extract. Sift together and beat in all at once flour, baking powder and salt. Beat just until smooth. Pour into prepared pan. Bake just until cake tests done at 375 degrees F for 12 to 15 minutes.

Loosen edges and immediately turn upside down on a towel sprinkled with confectioners' sugar. Spread cake at once with Clear Lemon Jelly Filling and roll up beginning at short end. Wrap in towel.

Clear Lemon Jelly Filling:
3/4 cup granulated sugar
3 tablespoons cornstarch
1/4 teaspoon salt
3/4 cup water
1 teaspoon grated lemon peel
1 tablespoon butter or margarine
1/3 cup lemon juice
4 drops yellow food color (optional)

Mix sugar, cornstarch and salt in saucepan. Stir in water gradually. Cook, stirring constantly, until mixture thickens and boils. Boil and stir 1 minute. Remove from heat. Add lemon peel and margarine. Stir in lemon juice and food color; cool. If filling is too soft, refrigerate until set.