Mickey's wish for a surprise-free birthday ends up becoming the biggest surprise of his life.
Mickey gathers his friends together to tell them that his birthday is coming up, but he doesn't want any surprises this year.
The next morning, things seem to go smoothly for Mickey, but everyone else is disappointed with how Mickey's birthday cake turns out. They want to make a bigger cake for their pal Mickey.
At Donald's boat, Mickey knocks on the door and finds that he is gone. He tries Goofy's house next, then Minnie's house, and wonders where everyone went.
At the park, everyone wants to make a larger-sized birthday cake than normal. Meanwhile, Mickey realizes that everybody's off planning his... SURPRISE PARTY!!
Goofy, Pete, and Horace put a big candle on a larger-sized cake, but Minnie still doesn't think it's big enough, and a giant bulb appears above her head and turns her evil.
Mickey gets chased by the giant cake and his conscience tells him to go save his friends. Mickey regains his confidence and gets ready to save his friends. To escape, Mickey makes Goofy's head into a helicopter to save Donald, Daisy, and Pete. Next, they save Horace, Huey, Dewey, Louie, Clarabelle, and Ludwig but land on top of the cake. Mickey hears Evil Minnie's "bigger" catchphrase, and tries to remove the big bulb from Minnie's head but he and everyone else get trapped. Mickey is sad but he has an idea: his birthday wish. He blows out a candle, causing a glowing spirit of himself in a birthday hat to appear, saying, "Minnie, if you can hear me, I just want you to know it isn't the size of the cake that matters, but the size of the heart that bakes it." Minnie suddenly regains her senses and turns back to her good self, remembering Mickey's words. She removes the big evil bulb and shatters it. She starts falling but Mickey, Donald, and Goofy catch her. The cake shrinks down to its original size, and the four friends fall onto the cake, splattering it all over the place. As everyone emerges from the damaged cake, Mickey slurps the strawberry icing. Minnie apologizes to Mickey for the giant cake as it turned out to be a big surprise after all. Mickey agrees, but he is happy this time and gives her a taste of the icing. Minnie hugs Mickey as she and the others sing "Happy Birthday" to him as the episode ends.
- Mickey Mouse
- Minnie Mouse
- Donald Duck
- Daisy Duck
- Huey, Dewey, and Louie
- Clarabelle Cow
- Horace Horsecollar
- Ludwig Von Drake
- Chris Diamantopoulos - Mickey Mouse
- Russi Taylor - Minnie Mouse
- Tony Anselmo - Donald Duck
- Tress MacNeille - Daisy Duck
- Jim Cummings - Pete
- Bill Farmer - Goofy
- April Winchell - Clarabelle Cow
- Corey Burton - Ludwig Von Drake
- This is the sixth episode to be seven minutes in length.
- This episode was released early on YouTube in some countries on November 17, 2018.
- An instrumental of Minnie's song from "The Birthday Song" can briefly be heard.
- A portrait of Matey McDuck from the Carl Barks comic "Back to Long Ago" can be seen next to the front door of Donald's boathouse.
- Goofy's house in this episode is the same one seen in "Goofy's Grandma". Additionally, a sandwich can be seen on the ground inside the house, possibly as a reference to "Goofy's First Love".
- Mickey had no problem with having a surprise party in Mickey's Birthday Party.