Lightly grease a 15 x 10 x 1 inch baking pan and line with wax paper; grease and flour the paper. Set aside.

In a mixing bowl, beat eggs on high for 5 minutes. Gradually beat in sugar until thick and lemon colored. Add pumpkin and lemon juice.

Combine flour, cinnamon, baking powder, salt and nutmeg; fold into pumpkin mixture. Spread batter into pan and sprinkle with walnuts.

Bake at 375 degrees for 15 minutes. Immediately turn out onto a kitchen towel dusted with powdered sugar. Carefully peel off paper and roll cake up in a towel (start with the short end). Let cool (at least 1 hour). It should be completely cooled before unrolling or it will crack.

Cream Cheese Filling: Mix filling ingredients with mixer.

Carefully unroll the cake. Spread filling over cake to within 1 inch of edges. Roll up again and place on a serving platter.

Cover and chill until serving. Dust with powdered sugar if desired.