Preheat oven to 350 degrees F (175 degrees C). Grease and flour jelly roll pan. (I use a 15x18 inch pan lined with waxed paper and then greased and floured.)
Beat eggs with electric mixer for 2 1/2 minutes. Add sugar slowly while still beating. Beat for 3 1/2 minutes more. Fold in pumpkin and lemon juice.
Mix together the flour, cinnamon, nutmeg, ginger, salt and baking powder. Fold into batter. Spread batter onto prepared pan. Bake for 15-18 minutes. Remove from oven and allow to cool enough to handle.
Remove cake from pan and place on tea towel (cotton, not terrycloth). Roll up the cake by rolling towel inside cake and place seam-side down to cool.
Prepare the frosting by blending together the sugar, cream cheese, butter and vanilla.
When the cake is completely cooled, unroll cake and spread with cream cheese filling and roll up again without the towel. Wrap with plastic wrap. Refrigerate until ready to serve. Sprinkle with confectioners sugar and slice into 12-15 servings.