In a large pot melt:
400 grams (14.11 ounces) of salted butter.
Then add:
The finely grated zest from one orange.
1/2 cup custard powder
1 cup sifted icing (powdered) sugar
3 and 1/2 cups plain flour.
Mix well.
Shape into small balls, then place on baking paper lined trays.
Press down with a fork.
Bake at 180 Celsius ( 356 Fahrenheit) for 10 - 15 minutes until slightly golden.
Cool.
Join with Orange Icing:
Beat 150 grams (5.29 ounces) of soft butter with the juice of one fresh orange.
Add 1 and 3/4 cups icing sugar.
Beat until creamy.
Join biscuits.
Yield - 54 single biscuits or 27 joined.
The unjoined biscuit can be sprinkled with Icing (powdered) sugar for serving.