Sometimes you just need a named brand to get the job done.
What Fox's have done is removed all of the elements that can so easily go wrong in a good biscuit when it's dunked - fondant fillings, flimsy construction, nuts and the most controversial of all, chocolate. You're left with a true pioneer - a simple, yet distinctly delicious creation.
Unfortunately it isn't esteeemed enough to be regarded as the classic that it so rightly has become in the hearts of biscuit connoisseurs.