birthday dessert plate with a message
A plate of dessert, typically cake, with a birthday message written in icing. Common in restaurants and cafes for celebrations.
wasei-eigo (Japanese-coined English), from birthday plate
For my friend's birthday, I ordered a birthday plate at the restaurant.
On the birthday plate, 'Happy Birthday' was written in chocolate.
Variant with interpunct; less common but still seen.
Wasei-eigo from English 'birthday' and 'plate'. Not a direct borrowing; the meaning is specific to a dessert plate with a birthday message.