Yellow cake lemon filling with white buttercreme icing

Cake sugar 50.7% , flour 24.6% , water 12.3% , soya oil 6.2% , egg 3.1% , egg white 1.5% , modified corn starch 0.8% , contains 2% and less of 0.4% , salt 0.2% , Raising agent 0.1% , vital wheat gluten 0.0% , Emulsifier 0.0% , artificial 0.0% , natural flavouring 0.0% , b-carotene 0.0% , dextrose 0.0% , maltodextrin 0.0% , E414 0.0% , partially hydrogenated soybean oil 0.0% , icing sugar 0.0% , fat 0.0% , corn syrup 0.0% , water 0.0% , contains 2% and less of 0.0% , E330 0.0% , corn starch 0.0% , modified corn starch 0.0% , high fructose corn syrup 0.0% , dextrose 0.0% , maltodextrin 0.0% , E412 0.0% , E410 0.0% , E307 0.0% , natural and artificial flavouring 0.0% , E171 0.0% , E133 0.0% , E132 0.0% , E102 0.0% , E133 0.0% , E102 0.0% , E110 0.0% , E129 0.0% , E129 0.0% , E127 0.0% , E132 0.0% , E110 0.0% , E338 0.0% , E202 0.0% , E211 0.0% , lemon filling-water 0.0% , high fructose corn syrup 0.0% , corn syrup 0.0% , sugar 0.0% , modified corn starch 0.0% , palm oil 0.0% , E330 0.0% , sodium citrate 0.0% , lemon pulp 0.0% , concentrated lemon juice 0.0% , E211 0.0% , E202 0.0% , salt 0.0% , E418 0.0% , lemon 0.0% , E471 0.0% , E490 0.0% , E171 0.0% , E435 0.0% , E102 0.0% , E110 0.0%