Pre-heat your oven to 180°c (or 160°c for a fan assisted oven) and line a couple of baking trays with greaseproof paper. Set aside.
In a large bowl, cream, together your butter/margarine and sugar until it is light and fluffy. Add the egg and mix until combined.
Sift the flour into the mixture and mix to form a somewhat stiff dough. Gently knead the dough on a well floured surface, before rolling to around 1cm thick. Using a circular or pumpkin shaped cutter, cut your biscuits and transfer them to your prepared baking sheets.You should be able to cut 20-24 biscuits, depending on the size of your cutter - these will be sandwiched together, giving you half as many completed biscuits.
Bake in your pre-heated oven for about 10-12 minutes until the edges of the biscuit are just golden.
When still warm but cool enough to touch, add a teaspoon of the chocolate spread to the under side on of half your biscuits, and pop the other half on top of these to sandwich together. Leave to cool completely before decorating.