120g icing sugar
120g custard powder, sifted
340g plain flour
4 tablespoons icing sugar
1 tablespoon soft butter
1 teaspoon vanilla essence
a little water
Cream the butter and icing sugar.
Add the sifted custard powder and flour a little at a time and mix well into a dough. Roll into small balls, flatten slightly on a tray and press down with a fork.
Bake for 15-20 minutes at 160degC. Cool on trays.
Make the icing by mixing all ingredients together, adding water a little at a time until the icing is spreadable but not too runny.
Ice one biscuit and top with a second.