First of all place all the ingredients (except the demerara sugar) in a bowl and mix them together to form a stiffish dough.
Now, because the mixture is sticky, flour your hands then shape lumps of the mixture with your hands to form walnut-sized balls.
Next tip a small heap of demerara sugar onto a working surface and place a ball of mixture in the sugar. Flatten it slightly, flip it over and place it (sugared side up) on the baking sheets.
The biscuits will spread, so allow some room for expansion.
Bake them, one sheet at a time, near the centre of the oven for 18 minutes, or until the biscuits feel firm when tested with the fingertips.
Leave them to cool and harden slightly on the baking sheet before transferring them to a wire cooling tray with the aid of a palette knife.
Store them in an airtight tin.
Pre-heat the oven to 180°C, gas mark 4