Dissolve 1 package lemon Jello in 1 cup boiling water and cool. Mix 1 package Duncan Hines Lemon Supreme Cake mix, 3/4 cup Wesson oil, and 4 unbeaten eggs, added one at a time; add cooled lemon Jello and pour into 9 x 13 x 2 inch pan that has been greased and floured. Bake in 350 degree oven for 15 minutes; then reduce heat to 300 degrees for 30 minutes. After removing cake from oven, pierce all over with two tined fork and ice with 2 cups powdered sugar dissolved in juice of 2 lemons (while hot).