Cream the margarine and golden caster sugar together.
Tip the lemon zest or vanilla extract in with the egg, then beat into the margarine and caster sugar.
Mix in the flour until all the ingredients are combined.
On a floured surface, roll out the dough to the thickness of about 5mm, and stamp out your biscuits.
Lay the biscuits on a baking tray lined with non-stick paper and put in the fridge for a few minutes.
Bake at 170°C for 12 minutes or until the biscuits start to turn golden brown around the edges.
Leave on the trays for about 5 minutes and then transfer to a rack to cool down.
While the biscuits cool, colour your fondant by kneading it with small amounts of food colouring until you are happy with the colour.
How to prepare your royal icing:
Whisk the egg whites with a hand-held mixer until the mixture turns foamy and forms very floppy peaks.
Fold in the icing sugar and then whizz for one minute with the hand-held mixer.
Add a squeeze of lemon juice and then mix for a further minute with the hand-held mixer.
If the mixture is too stiff at this point, you can ‘let it down’ with drops of water until the icing flows nicely.
Transfer some of the royal icing into a disposable piping bag and snip off the bottom, so that a thin line of icing can escape.
When your biscuits are cool and your fondant and royal icing are ready, you can begin to ice your biscuits.
Roll out your fondant on a surface dusted with icing sugar until it is about 2mm thick.
Taking the same, cleaned, cutter that you used to stamp out the biscuits, stamp out several fondant shapes.
Brush the surface of one of the biscuits with a little water and stick one of the fondant cut-outs onto the biscuit.
Smooth the surface of the fondant with your finger tips to remove any bumps or rough edges.
Take up your piping back of royal icing and pipe dots, hearts, lace patterns, names – anything that fits your theme.
If you want to, you can use a food-safe pen to add details such as eyes, smiley mouths, whatever takes your fancy!
Recipe courtesy of Hannah Wiltshire, Baby Cakes