Use shaving cream to make a fake pie. Fill the pie tin with shaving cream until it looks exactly like a cream pie. Shaving cream works better than whipped cream because it washes off easily and will not stain clothing.
Fill the chef's hat with rags. Put the hat in the pie tin and arrange it so that it looks like a cream pie from a distance.
Sneak up on the victim of the pie gag from behind. Bring the pie around his head quickly and pull it back onto his face. Use the shaving cream pie for a prank on the victim or for a stage show. Use the chef's hat pie for a cleaner gag on film.