Mix together all filling ingredients in small saucepan; cook over medium/low heat until dates are soft. Cool; set aside. Make dough by creaming together butter and sugar in large bowl until light and fluffy. Add eggs; beat well. Add lemon juice and vanilla; stir. Sift flour; add baking soda and salt. Sift again. Add to creamed mixture; mix well. (Mixture will be somewhat soft.) Divide dough in half; place on well-floured surface. Roll each out into rectangles about 1 cm thick. Spread evenly with filling. Roll up as for jelly roll. Cover with plastic wrap. Slice 0.125 to quarter thick with sharp knife. Place on greased cookie sheets. Bake at 200ºC or about dozen minutes or until golden brown. Cool on a wire rack. (Cookies freeze well.) Yield 4-5 dozen.