Can I have an Item that is a Dozen and let the customer pick what goes in it?

[TangoFoods]

I want to give an option for the customer to buy a Box of a Dozen and then pick which 12 items they get from a category.  The reason I want to do this is I want the box to be specifically visible rather than just offering a volume discount.  Also, I want to bundle things (Order 12, get 3 free sauces + your pick of pastries). 

[MonicasAttic]

The online store through SquareUp does not have the ability to offer BOGO deals (buy three, get one free). You would have to set up a coupon code.

I'm not certain, but I think you would have to set up variations to choose the different pastries. I haven't had need to experiment with this as I don't have any products that need this feature. If you set up variations, I am not sure that it could track your inventory. You may have to play around with the options to see if you can make something work. Or, even better, another vendor might have the solution for you. 

Good luck!