cakeage

cake +‎ -age, modelled on corkage.

• IPA^(key): /ˈkeɪkɪd͡ʒ/

cakeage (uncountable)

1. A fee levied by a restaurant on customers who bring their own cake (such as a birthday cake) rather than buying one on the premises.
   • 2003, Kathleen Thompson Hill, Napa Valley: Land of Golden Vines, page 171:

     Corkage fee: $10.00 per 750 ml bottle; "cakeage" (if you bring your own birthday cake) $2.25 per person.

   • 2010, Lisa Dempstere, The Australian Veg Food Guide 2011, page 191:

     Large groups are easily accommodated, though be warned, a 'cakeage' fee of $1.50 per head will be charged to birthday revellers.

   • 2016 January 13, Kim Severson, “Restaurants Counter Outside Cakes With Cakeage Fees”, in The New York Times‎:

     "[r]estaurants often charge customers to cut and plate the cake. Sometimes they add a scoop of ice cream. The practice has come to be called cakeage. It’s a play on corkage, the fee a restaurant levies to open a bottle of wine brought by the customer."