Preheat the oven to 180 C / Gas 4. Put the flour, sugar, baking powder and cocoa powder in a large mixing bowl and stir together with your hands until it's a uniform colour.
Add butter and work it in with hands until it becomes like breadcrumbs. Stir in the chocolate chips. Slowly add the milk a bit at a time, while working with your hands until a dough forms - if you use to much milk and it becomes sticky just add a little flour to bring it back.
Then lightly flour your work surface and roll out to about 2cm thick and then cut. Place on baking tray and brush with milk.
Bake for 12 to 15 minutes, test with a toothpick or skewer, and if it comes out clean then they are cooked. Lastly and most importantly. . . enjoy!