A fairy cake is a light little bun with icing and creme butter in it. They're widely popular in the UK, and tend not to pile on the icing in the same way that American bakers do with cupcakes. They also are traditionally made with a lighter sponge cake as opposed to the thicker butter cakes used in cupcakes. Alternatively, a fairy cake is a type of cupcake with its top cut off and replaced in two pieces, like wings. These are also called butterfly cupcakes.

Of course, the petite fairy cakes are named as such because of their size -- small enough to be served to the tiny mythical creatures. The word "fairy" (or "fairie") appeared around 1300, referring to "enchantment" and "magic."
Super fluffy fairy cakes will melt in your mouth.
Three easy techniques for icing fairy cakes—spreading, piping, and dipping.

Check the fairy cakes at the minimum baking time.
by cvf October 23, 2013
Cunt especially of the lesbian variety, especially with a butterfly in butter cream topping
Licking out all the butter cream from my girlfriend's fairy cake is making me into a very fat lesbian
by bealfakelesbian September 17, 2009