Start by preheating your oven to 170 degrees C (160°C for fan ovens).
Take a large baking sheet (or a baking tray will work just fine) and line it with baking paper or greaseproof paper.
If the butter is soft, cream it by hand with the caster sugar. If the butter is fresh from the fridge it might be helpful to use a machine at this stage.
Gently stir in the plain flour a little at a time, then add most of the coconut (but save a little for decoration).
Bring the mixture together as a dough, then roll it out onto a floured work surface to about the thickness of two coins.
Use a cutter or a knife to shape the biscuits into rectangles, then take a knife to etch the word NICE into the surface.
Place on the baking tray and sprinkle the granulated sugar and remaining coconut over the top.
Bake for 14 minutes, then leave to cool before enjoying!