Babes In Toyland (1986)
Someone on MetaFilter very helpfully pointed me toward this movie as a veritable Doom Cake cluster-bomb. Thanks, troll!
In addition to the sort-of-says-it-all example provided above (skip right to 2:40), you’ve also got cakes in the background of the Cookie Factory, just before it’s raided (that’s where bad little girls get threatened with the flour grinder). Cake-intensive factory encounters seem to be the norm in Toyland, and most of them seem to involve children in jeopardy. Fun!
The main specimen here — in which young Barrymore base-jumps into an enormous layer cake — is rather unique among the other Doom Cakes we’ve seen: it’s a glimpse of the childish desire to wreak messy havoc or suffer tragic accidents without any consequence whatsoever, a recurring theme (oddly enough) in most of the entertainment that adults engineer for children.