1. Preheat oven to 180°C (350°F). Line a baking tray with parchment paper.
2. Cream the margarine (or butter) with sugar until light and fluffy.
3. Stir in cocoa, flour, coconut, salt, and vanilla. Mix until the dough comes together.
4. Roll small pieces into balls and place on the prepared tray.
5. Gently press each one down with a fork.
6. Bake 10–15 minutes, until bottoms are lightly golden. Don’t overbake; they firm up as they cool.
7. Cool on the tray for 5 minutes, then transfer to a wire rack.

They keep well in an airtight tin for up to a week, if they last that long.