Take 6 large tbsp of softened butter (not melted) in a bowl add 1/2 cup of sugar, 1/4tbsp of salt and whisk well.. add 1/2 tbsp vanilla extract and an egg yolk(optional).whisk again uttill it doubles... then add 10 tbsp of fresh cream or milk. Add 5-10 tbsp of coco powder (add according to how chocolaty you want biscuits to be).... blend well with a spoon/spatula.
Now take 1 cup of maida and 2 tbsp of corn flour and swift in the mixture... blend... when it becomes a smooth paste