2 cups Self Raising flour
1 cup butter
1 cup sugar
4 tbsp custard powder
2 large eggs
pinch salt
Beat butter and sugar to a cream, add in eggs and make into a paste with dry ingredients. roll into walnut sized or smaller balls and press down to mark with the back of a fork. bake in a moderate oven till light brown. (you may need to add a little more flour in humid weather)
when cold join together with the following icing
4 tbsp icing sugar
2 tbsp custard powder
2 tbsp butter
mix together and use to join pair of the biscuits. (in cold weather it may help to put the mixing bowl into hot water - in hot weather it may need the odd spell in the fridge!)