Beat the eggs in the electric mixer on high speed for 5 minutes.Gradually beat in the sugar. Add the pumpkin and the lemon juice and beat until well blended. Combine the dry ingredients in a separate bowl, then fold into the pumpkin mixture. Spread evenly into a greased and floured pan. Sprinkle the walnuts over the batter. Grease and flour 15 x 10 x 1â€‘inch panBake in the center of a 375-degree oven for 15 minutes.Turn out onto a lintâ€‘free dish towel that is sprinkled with confectioners’ sugar. Very carefully roll, beginning with long side, rolling towel and cake together. Cool completely.Combine filling ingredients in a medium electric mixer bowl. Beat until smooth. Unroll cake. Spread the cream cheese filling evenly over the cake. Re-roll and place, seam side down, on a tray. Refrigerate until ready to serve.Serves 8 to 10.