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 1/2 inch thick. Spread evenly with filling. Roll up as for jelly roll. Cover with plastic wrap. Slice 1/8 to 1/4 thick with sharp knife. Place on greased cookie sheets. Bake at 400 for about 12 minutes or until golden brown. Cool on a wire rack. (Cookies freeze well.) Yield 4-5 dozen.