Preheat oven to 375°F. Line two baking sheets with parchment paper or silicon baking mats.
In a food processor or blend, pulse 16 of the Biscoff cookies until you have about 1 cup of fine crumbs. Set aside. Roughly break up another 8 Biscoff cookies into chunks and set aside. Reserve the 8 remaining Biscoff cookies for decorating the tops of the cookies at the end.
In a large bowl, cream the butter, brown sugar, and granulated sugar for 3-4 minutes.
Add the eggs and vanilla, then beat again, stopping to scrape the bottom and sides of the bowl.
Add the cookie butter and mix until combined.
Add the flour, reserved 1 cup of finely crushed Biscoff cookie crumbs, cornstarch, baking soda, baking powder, and salt. Mix on medium-low speed just until combined, stopping to scrape the bottom and sides of the bowl.
Stir in the reserved broken up Biscoff cookies and white chocolate chips.
Use a large ¼ cup cookie scoop to make evenly sized balls of cookie dough. Roll them gently between your hands for perfectly uniform cookies, if desired. Space the cookies a few inches apart on the parchment paper-lined baking sheets so they have room to spread while baking. (See notes if you want to stuff the cookies with additional cookie butter.)
Bake for 8-10 minutes just until set but slightly underbaked in the middle so they stay soft.
Remove from the oven and press half of one of the reserved Biscoff cookies into the top of each cookie along with a few additional white chocolate chips. Let cool on the baking sheets for 10 minutes before transferring to a wire rack to finish cooling.