means A crumbly, biscuit-like or sweet cake, traditionally split and layered with fruit and cream, as in strawberry shortcake.

from A compound of "short" and "cake," dating to the 16th century. The key word is "short" in its old baker's sense — meaning rich with fat, which keeps the flour's gluten strands "short" so the result crumbles rather than stretches. It's the same "short" that gives us "shortening" and "shortbread." So the cake isn't lacking in height; it's deliberately tender and breakable, which makes the essence's joke truer than it looks.