Mix flour,cocoa powder, corn starch and salt together, keep a side.

In another bowl add sugar and butter, use mixer and mix till the mixture become light and fluffy.

Gradually add flour mixture and mix to make dough. Put in the fridge for 10 minute.

Remove from fridge and divide into 12 small round balls. Arrange on the baking tray, make a space in between, use a fork and press each ball, then garnish on top with sprinkles.

Bake in a per heated oven of 170c for 7-10 minutes.