The story is about Mr. Mixie Dough, who "lives away up in the sky in a place called "Behind-The-Clouds-Town". But unhappiness creeps over the town because the King Misty "cannot get a Happiness cake for his little boy's birthday." Mr. Mixie Dough, along with all of the other bakers, compete in making a "Happiness birthday cake" for the King's son's birthday.
The story focuses on Mr. Mixie Dough, who inhabits an elevated community called 'Behind-The-Clouds-Town'. As a result, unhappiness spreads throughout the town due to King Misty's inability to obtain a Happiness birthday cake for his child's birthday celebration. Mr. Mixie Dough, along with other bakers, participate in creating a "Happiness birthday cake" for the King's son.