Oven Logic: Marge's cake was so hard it broke a bullet-proof glass.
Previously On: Parodied. As part of another allusion to "24", this episode starts with a narrator treating it as a sequel to a previous episode. The narrator even mistakenly calls the cartoon "24" before correcting himself.
Serious Business: the bake sale and an attempt to disrupt it is taken by the hall monitors as a 24-style threat. Justified Trope on the bake sale (see As You Know above) and the stink bomb because it is something obscenely powerful.
Jack Bauer ends up calling in every CTU field agent away from a nuclear threat in Shelbyville to arrest Bart for his earlier prank call.
Squick: The bullies throw some rather gross ingredients into their stink bomb, including a possum placenta, a bottle of farts, sweat from a Goofy Suit and to top it off, some mouldy yogurt they stole from Homer earlier.