This image generator is free for now if you have an account at least and it's producing some pretty decent results. Here are some examples that haven't been finessed at all, just the straight output.

Might I ask what prompt you used to successfully get the faces covered in pie but not completely obscured?

Here's one of the prompts.

PHOTO of smirking athletic 19 year old woman in a shiny red latex bikini holding a whipped cream pie, a seated man wearing a suit is covered in pie, there is whipped cream all over the man's face and suit as if she has already hit him with several other pies, they are on an outdoor balcony on an

overcast day