Pinwheel Creams.
It may not exactly be re-inventing the Pinwheel biscuit, but unless I’m dunking, I sometimes find the straight single-decker variety a little dry.
The buttercream is either vanilla or chocolate.
The marbled biscuits came about simply by making use of the leftover doughs (no point being wasteful!)
I made the square-ish wavy-edged ones just for the sake of mild experimentation.