There is a Tax compliance requirement in certain States in Canada if 6 or more Sweetened baked products are Purchased in single transaction then there is no Tax. However, if customer purchases less than 6 quantity of any sweetened product then they are taxable.

This is a compliance requirement.

Please refer below for Example:

https://www.revenuquebec.ca/en/businesses/consumption-taxes/gsthst-and-qst/special-cases-gsthst-and-qst/food-services-sector-applying-the-gst-and-qst/groceries/sweetened-baked-goods-and-similar-products/