in a bowl add butter, sugar, essence and baking powder
beat until light and fluffy
add flour, mix well and knead a soft dough
divide the dough into 2 equal portions
add cocoa powder and milk in one portion and mix well
now divide each dough portion into 24 grape sized balls
for making cookie, take 3 balls of each dough
place these balls on a board alternatively in a circle and roll into a larger ball
then roll that ball between your hands and place on a greased baking tray
repeat the process with remaining cookies
bake cookies in preheated oven at 160 degree c for 12-15 minutes
remove from oven and let them cool
serve with tea or coffee or store in an air tight container