1) In a bowl, combine butter and sugar and beat till light and fluffy.
2) Mix in the vanilla essence and gently fold in the flour and chocolate powder.
3) Break down and roll the mix into walnut-sized balls.
4) Arrange on a baking sheet.
5) Dip a large fork in cold water and flatten the arranged balls.
6) If you choose to store instead of bake immediately, then open freeze the discs till frozen solid and pack into sealable container. To use frozen biscuit, remove from the freezer and arrange at least 5 cm (2 inches) apart on a greased baking sheet.
7) Place in oven for 12-15 minutes at 190°C, 375°F, Gas Mark 5.
8) Allow the biscuits to rest on the baking sheet for 1 minute to firm, then place on a wire rack and cool.
9) Sprinkle with cinnamon powder and serve.