In a mixing bowl sift flour, baking powder, powdered sugar and mix it well.
In another bowl beat, butter and sugar on medium speed with the help of electric beater for 2 minutes or you can use a wired whisk to cream the butter and sugar.
Now add milk, vanilla essence and mix it in cut and fold method for few seconds and then beat it for a minute.
Now add sifted dry ingredients, choco chips into the bowl of wet ingredients and mix it well with the help of a spatula. It will look like a thick batter, not dough.
Cover the bowl with cling wrap and keep it in the freezer for 30 minutes.
After 30 minutes take out the bowl from the freezer and you will see the cookie batter has become stiff enough to roll into the shape of cookies.
Take a small portion of the batter a, roll it in your palms and flatten it. Size of all the rolled cookies should be same otherwise baking time may vary.
Dust the tin with all-purpose flour, Keep rolled cookies into the dusted tin.
Repeat the same process for rest of the batter.
Sprinkle some choco chips on top and put the tin in preheated oven on 180 degrees for 15-18 minutes or until it gets baked.
All ovens are different so set the time according to your oven.
Once done immediately take out from the tin and transfer to cooling rack otherwise it will become hard and remove moisture.