From the Super Mario Wiki
Cake Maker is a Gaddget in Mario Party Advance. It can be obtained by completing the quest Locomotionless. Cake Maker can be used to activate a cake editor. The player can decorate and customize their own cake. The player can choose to add a fruit, a flavor, and color. Once the cake is done, the same custom cake can be edited the next time Cake Maker is used.
"Decorate a cake! But... try not to take a bite out of it. Trust us."