I thought a biscuit in the US was something you poured gravy on (we pour it on chips, but then your chips aren't big chunky greasy yet strangely tasty things are they?....). What the dwarves ate would I suppose be equivalent to cup cakes in the US? Like birthday cake, but about small enough to put in your mouth all in one go.
(I hasten to add, you would only put them in your mouth in one go if you were trying to snaffle them before your mother catches you stealing from the pantry.)