FOR THE CAKE: Beat egg yolks undil creamy. Add powdered sugar gradually and continue beating until smooth. Add vanilla, flour, cocoa, and salt. Whip egg whites with cream of tartar until stiff but not dry. Fold lightly into cake batter. Line shallow 8 x 12-inch pan with greased geavy paper and spread dough to thickness of about 1/4". Bake in a 325? oven for about 25 minutes let cool in pan for 5 minutes. Reverse pan onto a clean towel that has been dusted with powdered sugar. Peel off paper. Trim off crust edges. Roll cake and dowel. When cool, unroll cake and spread with filling; then reroll. FOR THE CHOCOLATE FILLING: Grate chocolate and add to milk so that it melts while milk is scalding. Cream sugar and eggs until light. Add flour to this mixture, stirring gently. Add scalded milk gradually, stirring constantly. Cook and stir until it reaches boiling point, but do not let it boil. Add vanilla; strain and cool. Spread on cooled cake and reroll. Dust roll with powdered sugar; slice, and serve. Serves: 8 to 10 Source: "Mountain Measures" --Junior Leauge of Charleston, WV ed. 1974 Recipe by: Mrs. John M. Slack, III Posted to MC-Recipe Digest by "Bill Spalding" on May 10, 1998