Preheat the oven to 350°F and line a baking sheet with parchment paper.
Add the cubed butter, sugar, and brown sugar to a mixing bowl or the bowl of the stand mixer fitted with the paddle attachment. Beat with a hand mixer or the stand mixer until creamed.
Add the milk and vanilla extract. Beat again until well combined.
Add the flour, baking powder, baking soda, and salt. Mix until just combined.
Stir in the white chocolate chips and Biscoff cookie pieces.
Split the dough into five equal pieces (~5oz each) and roll into balls. Place on the baking sheet, leaving room in between.
Bake for 12-14 minutes, until lightly golden. Immediately top each with 1/2 of a Biscoff cookie. Allow to cool slightly on the baking sheet, then enjoy.