Ahh .. this reminds me of the classic "what's a pie?" conversation or "is a Jaffa Cake a biscuit"?
I think Jaffa Cakes are cakes not biscuits, a pie has to have pastry and a cake is "A sweet baked food made of flour, liquid, eggs, and other ingredients, such as raising agents and flavorings."
- Okay, I DuckDuckGo'd it because I haven't thought of it before.