Yellow cake American British noun phrase
1. To refer to a sponge cake that is made of egg yolks
I intend to buy a yellow cake and a rose bouquet to surprise Jenny at her birthday.
2. To refer to uranium oxide powder which is made by milling uranium ore
Yellowcake is an indispensable material to produce nuclear weapons.
To write something
Yesterday, he put pen to paper and replied to all letters from his fans.