Add-On Surcharges

Is there a way to set something up to allow guests to purchase the add-on surcharge options after they complete their initial booking? Say we offered a birthday cake, and they didn't buy it when they booked, but then decided it would be easier to have us provide it. Is there a way to set up a page, or an email with the options, to ask them one more time before they check in if they want any of the options?