Preheat the oven to 350. Add butter, brown sugar, sugar, and cookie butter to a bowl. Mix for 2-3 minutes until smooth and lighter.
Add egg and vanilla and mix until just combined.
Add flour, baking soda, and salt. Mix until dough just comes together. Add white chocolate chips and biscoff cookie pieces. Pulse a few times until the mix-ins are just distributed.
Scoop out 1/2 cup of dough and form in a ball. Place up to 6 dough balls on a lined or greased baking sheet.
Bake in the oven for 10-12 minutes, until cookies are just golden brown on top. Once the cookies are out of the oven, gently press half a biscoff cookie into the top of the cookie.
Let the cookies set up for at least 30 minutes. Enjoy!