Preheat the oven to 180°C/350°F/Gas Mark 4, 10 minutes before baking. Lightly grease a baking sheet
Cream together the butter and sugars until light & fluffy
Gradually stir in the egg and vanilla essence and beat until well blended
In another bowl, sift together the flour, baking powder and bicarbonate of soda
Add to the butter & sugar mixture and beat together until smooth. Fold in the rolled oats and coconut with a metal spoon or rubber spatula (I found the mix too stiff for a rubber spatula)
Roll heaped teaspoonfuls of the mixture into balls and place on the prepared baking sheet about 5cm/2ins apart and flatten each ball slightly with the heel of the hand
Transfer to the preheated oven and bake for 12-15 minutes, until just golden
Remove from the oven and transfer the biscuits to a wire rack to completely cool
Despite being a greedy pair, we can't polish off 40 cookies in the 3 or 4 days that they remain fresh. I cooked half the batch and put the other post-flattened, pre-baked cookies in the freezer. I put them on a wire rack to freeze (they'd stick like glue to a baking sheet if used) then transferred them to a zip-lock freezer bag. To make the next batch just allow the cookies to defrost for about half an hour before baking as normal.