From... the movie that I'm not going to name because you're better off not watching it whole. It's a huge shame because it has a bunch of good slapstick and goofy gags scattered across poorly done ones and skewered onto a plot that unfortunately comes off as awkwardly morbid and poor taste. But this scene... in terms of pie fights, this is stuff of legends. I'm sad it's stuck in this wreck of a movie, but thankfully this scene is one of those which were done right and were not ruined. I think just this one scene is a better watching experience than the whole movie.
I might do a clip compilation of other good slapstick goofs from this movie later.