These classic fudgy, rich biscuits are a favourite.
In a medium bowl, mix together the cocoa, sugar and oil. Add the eggs, one at a time beating well between each addition.
In a separate bowl, sift together the flour and salt, add the baking powder and vanilla extract and then fold this into the cocoa mixture.
Cover and let cool for at least 2 hours in the fridge, giving the biscuits the crinkle effect.
Preheat oven to 180°C and grease and line two baking trays with paper.
Roll dough into balls about the size of a walnut, roll with the icing sugar and then place on the baking tray.
Bake for 10 minutes then let biscuits cool on a wire rack.