Line a greased 15-in. x 10-in. x 1-in. baking pan with waxed paper; grease the paper and set aside.
In a large bowl, beat the eggs on high speed for 3 minutes. Gradually add sugar, beating until mixture becomes thick and lemon-colored. Beat in the buttermilk, oil, vinegar and vanilla. Combine the flour, baking powder and salt; fold into egg mixture. Spread into prepared pan.
Bake at 350° for 12-15 minutes or until cake springs back when lightly touched. Cool for 5 minutes. Invert onto a kitchen towel dusted with confectioners' sugar. Gently peel off waxed paper. Roll up cake in the towel jelly-roll style, starting with a short side. Cool completely on a wire rack.
In a small bowl, beat cream cheese and butter until smooth. Beat in confectioners' sugar and vanilla. Unroll cake; spread filling over cake to within 1/2 in. of edges. Roll up again. Place seam side down on a serving platter. Dust with additional confectioners' sugar. Refrigerate for 1 hour.