Mix flour and sugar together. Bring butter, oil and water to a boil and pour over flour mixture. Beat together. Add remaining ingredients and beat well. Pour into a greased and floured jellyroll pan. Bake at 350 for 20 minutes.
For icing mix all ingredients and spread over warm cake.
Recipe by Fencerow to Fencerow at http://www.fencerowtofencerow.com/2015/03/23/yummy-easy-vanilla-sheet-cake/