I wanna say it's a Treehouse of Horrors where Homer got turned into Robocop

Watched it last night! Treehouse of Horor 2! Burns takes homers brain and puts it in his robot. Hello there, I'm your daddy!

Fun fact, we watched it again because we watched Obsession for Halloween and the creator credits Treehouse of Horror 2 with direct inspiration for the premise of the film. (It was also interesting that he obviously took other small quirks from the other stories too)

Good reminder, eating too much candy can give you horrible nightmares, like Bart loving his father.