I love doing brush embroidery on a cake. It is very simple to do but it takes some time so it is a lovely way to pass the afternoon deep in thought. Let me teach you how.
You will need ...
parchment paper or cake
pen or food marker
(Beat together 1/4 cup meringue powder and 1/2 cup water until frothy.
Stir in 1 lb confectioners sugar and beat until glossy but no longer shiney)
Sketch your design .. on parchment to practice and on your cake for real.
Pipe the outline of your shape in royal icing using a #2 tip.
Find a very thin brush.
While your icing is still wet, place your BARELY damp brush into the icing and drag towards the center of your design.
Continue dragging until your design is complete.