Preheat your oven to 350°F (175°C). Line your baking sheet with parchment paper to ensure the cookies don’t stick.
In a medium bowl, whisk together the cake flour, all-purpose flour, cornstarch, ground cinnamon, baking powder, baking soda, and fine sea salt. Set this mixture aside.
In a large bowl, using an electric mixer, beat the softened unsalted butter, cookie butter, cream cheese, light brown sugar, and granulated sugar until the mixture is light and fluffy. This should take about 2-3 minutes.
Add the large egg, egg yolk, and vanilla extract to the butter mixture. Beat until fully incorporated.
Gradually add the dry ingredients to the wet mixture, mixing until just combined. Be careful not to overmix; you want to maintain a tender cookie.
Gently fold in the milk chocolate chips and coarsely crushed Biscoff cookies. This step adds texture and flavor, so make sure they are evenly distributed.
Using a cookie scoop, portion out the cookie dough onto the prepared baking sheet, spacing them about 2 inches apart. This allows room for spreading while baking.
Bake the cookies in the preheated oven for 10-12 minutes or until the edges are lightly golden. The centers may look a bit underbaked, but they will continue to firm up as they cool.
Once baked, remove the cookies from the oven and let them cool on the baking sheet for about 5 minutes before transferring them to a cooling rack. Allow them to cool completely before indulging in these Chocolate Chip Biscoff Cookies.
