The exploding pie is a pie that contains a bomb inside and only appears in the episode "Dying for Pie."
It looks like a regular berry pie, with a golden tan crust and filling inside. The flavors the pies come in include apple, raspberry, and blueberry.
Role in episode
It is Employee Brotherhood Day at the Krusty Krab, so Squidward buys a pie from a group of pirates for SpongeBob. However, the pirates inform him that they're actually bombs rather than pie. Squidward is left disappointed, saying that he was planning on buying one for somebody. As a means to get cash, the pirates tell him that they were the bomb claims were just a hoax, and they are willing to sell one to Squidward, which he then buys.
Once SpongeBob eats the pie, Squidward then realizes that it was actually an exploding pie and decides to make SpongeBob's last few hours of his life meaningful as a result.
However, it is revealed that SpongeBob did not eat the pie and it was in his pocket the whole time for him and Squidward to share. Unfortunately, he trips and the pie lands on Squidward's face, causing it to blow up, destroying Bikini Bottom in the process.
The pie is made in a factory, not homemade, as revealed in the episode.