Preheat oven to 170°C and grease or line a tray with baking paper.
Beat butter, sugar, vanilla essence and egg until smooth (don’t over beat). Sift dry ingredients and stir into butter mix, then mix in the chocolate. Roll heaped teaspoon sized balls of mixture and place on tray, press lightly with a fork - allow space for spreading. Bake for 8 minutes, remove and stand for 5 minutes before transferring to a wire rack to cool.
You can use milk, dark or white chocolate, or try a mix of dark and white chocolate.