From the Super Mario Wiki
A Shroom Choco-Bar is a recipe found in the game Super Paper Mario made by Dyllis. It is a shroom-flavored bar, and also has a red wrapper. It fills 15 HP and cures Poison. It entrances fungus gourmets the universe over. It is made by mixing a Mild Cocoa Bean with a Shroom Shake, and can also be bought in Howzit's shop in Outer Space.
Squirps wanted chocolate so he could split into two and open the door to the Whoa Zone. Other kinds of chocolate bars would also do the trick. The other kinds of chocolate bars are Sweet Choco-bar and Golden Choco-bar.
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