Muffet figured out if she can't find people to buy desserts for her charity, she could just buy all the stock herself! Of cause she could just make a money donation, nor does she actually need to eat everything she buys but she doesn't seem like the type of person to think more then one step ahead...

Done by: https://www.deviantart.com/edgeofmind

EDIT: Me and a commenter came up with a rhyme to go with it. I call it...

Big Miss Muffet
little miss muffet started to puffet, growing large everyday
she farted and farted but the shrinking never started,
so the bake sale had a delay