Add the cocoa powder, baking powder and milk and mix.
Add the raspberries and either continue to blend with the food processor or mix by hand. It depends if you prefer the raspberries to be smoothly mixed in or to have pieces of fruit in the finished cookie.
Stir in the chocolate chips by hand.
Grease or line a baking sheet and blob the mixture onto it, about 1 1/2 tablespoons of mixture per blob. Squash the blobs with the back of a spoon to flatten them into discs about 1/2" thick.
Bake for 12-15 minutes and then leave to cool completely before removing from the tray.