Unfortunately if you work for yourself part of doing cakes is dealing with the business side of things. At this point I would do what you can to collect. Send an email so it is in writing, saying. Just a reminder the amount for ingredients, etc was $ and was due on whatever date and payment is now past due, please pay promptly.
In the future, even for family for a wedding cake I would do a contract or at minimal an email that receives confirmation from the other party with specific terms, cake will cost x amount of dollars, deposit in the amount of x is due on tbd date and balance is due X date.
I would get wedding cakes paid in full prior to event.
guessing that it goes with this topic
http://cakecentral.com/cake-decorating-ftopict-681701-.html
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