Work together all the ingredients for the pastry. Put the dough in a plastic bag and refrigerate for at least 30 minutes.
Roll out the dough to a thickness of 2-3 mm on a floured surface. Cut out shapes with a cookie cutter. Place the biscuits on a parchment-lined baking sheet and bake in the centre of the oven at 175°C for about 15 minutes.
Leave to cool on a wire rack. Melt the butter or margarine in a pan.
Break the chocolate into pieces and place in the melted fat. Melt at a low heat. Leave the mixture to cool for an hour, then beat it with an electric whisk at high speed.
Spread the filling on half of the biscuits and gently press the other biscuits on top.
Mix together all the ingredients for the icing. Ice the biscuits using your imagination.
Tip: You can also serve the biscuits singly without the filling. Make a hole in some of them and hang them up as Easter decorations.