Mix the flour, ginger and sugar thoroughly.
Melt the butter in a saucepan and add the treacle and bring to the boil, stirring continuously.
Turn off the heat and add the other ingredients, mixing vigorously with a wooden spoon.
When it has cooled sufficiently to handle, scoop up a small quantity of the mixture with a dessertspoon and push off with a teaspoon onto a well greased baking tray or sheet.
Flatten slightly with a fork and leave space between each one to allow it to spread.
Cook at 160C/325F/Gas Mark 3 for 25/30 minutes.
Use a palette knife to lift the biscuits off the tray and store in an air-tight container.