On Bing, "getting hit with a custard pie in her face" "a custard pie smashing on her face" "a custard pie splattering on her face" (for when Bing is being difficult). Sometimes "cream" for "custard" will work, sometimes it gets the Dog.
I specify "custard" or "cream" because sometimes I was getting weird fruit pies. Surprisingly "blueberry pie" worked better for me than "cherry pie."
Yeah I know there are obscene meanings for some of these terms. I don't know why Bing cares.
Yeah, "custard" works best. I also find that "wearing custard on her face" is a way to increase coverage. Also specify a facial expression if you want to see the target's face.