Correct spelling, explanation: the correct form is marshmallow and the term marshmellow is a common misspelling. The word marshmallow originates from the name of the mallow plant species (Althaea officinalis), which grows in marshes. Historically, the root of the marshmallow plant was used to make a sweet, sticky treat, which evolved into the modern confectionery we know today. Using marshmallow is correct and aligns with the historical, etymological, and standardized spelling in English. Marshmellow is just a mistake.

Definition of marshmallow:
Noun, a soft, often white, candy made mainly of sugar
After toasting the marshmallow over the campfire, she carefully sandwiched it between two graham crackers with a piece of chocolate to make a perfect s’more.
The hot chocolate was topped with a large marshmallow that slowly melted, adding a sweet and creamy texture to the drink.

Collocations with marshmallow:
Some of the most commonly used collocations include:
1. Toasted marshmallow: a marshmallow that has been heated and browned, typically over a fire.
She enjoyed the gooey, caramelized flavor of a toasted marshmallow straight from the campfire.
2. Marshmallow fluff: a soft, spreadable mixture made from marshmallows, often used in desserts.
He spread marshmallow fluff on his sandwich to make a sweet and sticky treat.
3. Marshmallow topping: marshmallows used as a topping, commonly for desserts like ice cream or hot chocolate.
The hot fudge sundae was finished with a generous layer of marshmallow topping.
4. Marshmallow cream: a creamy mixture made from marshmallows, similar to marshmallow fluff, used in various recipes.
She added marshmallow cream to her homemade fudge to give it a sweet, smooth texture.

Incorrect spelling, explanation: you should not use marshmellow instead of marshmallow. The only correct form is marshmallow and this version is the standard and accepted spelling in English. Dictionaries, culinary references, and other authoritative sources all use this spelling. Using the correct spelling ensures clarity and consistency in communication. Changing it to marshmellow would be incorrect and could lead to misunderstandings or be perceived as a mistake.