Preheat your oven to 350°F (175°C).
Combine Dry Ingredients: In a bowl, whisk together the flour, cocoa powder, baking powder, and salt. Sieve and keep aside.
Cream Butter and Sugars: In another large bowl, beat the softened butter, powdered sugar until creamy and smooth. This usually takes about 2-3 minutes.
Add Milk and Vanilla extract.
Combine Wet and Dry Ingredients to a dough.
Roll out the prepared dough to a thickness of approximately 0.5 cm between two sheets of parchment paper.
Sprinkle chocolate chips over the rolled-out dough, then roll it again.
Using a fork, create diagonal dents on the rolled-out dough. Next, cut equal-sized squares from the dough.
Refrigerate the biscuits for 15-20 minutes.
Bake the cookies for 12-15 minutes or until edges are firm.