Lemon Square Cake Iced

White cake mix (sugar, bleached enriched wheat flour [wheat flour, niacin, reduced iron, thiaminemononitrate, riboflavin, folic acid], vegetable shortening[partially hydrogenated soybean & cottonseed oils withadded mono - and diglycerides, propylene glycol mono - anddiesters of fat, lecithin, and polysorbate 60], egg whitesolids, modified wheat & tapioca starch, leavening [sodiumbicarbonate, sodium aluminum phosphate, sodium acidpyrophosphate, monocalcium phosphate], non fat dry milk, salt, dextrose, natural and artificial flavor, xanthangum, guar gum, sodium stearoyl lactylate) , water,powdered sugar with corn starch (anticaking agent), icingbase (vegetable oil [partially hydrogenated soy andcottonseed], sugar, corn syrup solids, mono anddiglycerides, salt, artificial flavor, polysorbate 60), soybean oil, lemon flavor (water, natural flavors, xanthangum, citric acid, sodium benzoate, bha, yellow #5).