Preheat oven to 375°F. Line one or more baking sheets with parchment paper.

From the 14 oz container of cookie butter, measure out and set aside 1 cup for the dough. Using the remaining 1/2 cup, drop 24 small scoops (about 1 teaspoon each) onto a small piece of parchment or a small baking sheet and place them in the freezer while you make the dough.

In the bowl of a stand mixer (or using a hand mixer), add the room-temperature unsalted butter, light brown sugar, and granulated sugar. Beat on medium speed about 1 minute until combined.

Add the 1 cup of reserved cookie butter to the mixer and beat 2–3 minutes, until the mixture is lighter in color and fluffy. Scrape down the bowl as needed.

Add the 2 large eggs, the egg yolk, and the vanilla extract. Mix until just combined.

In a separate bowl, whisk together the all-purpose flour, baking soda, baking powder, and kosher salt. Gradually add the dry ingredients to the wet mixture and mix until just combined; do not overmix.

Stir in 1 1/2 cups of the white chocolate chips. Reserve any remaining white chocolate chips from the bag for topping.

Portion the dough into 24 balls, about 3 tablespoons each (roughly 70 g) and place them on a plate or baking sheet.

Remove the frozen cookie butter scoops from the freezer. Press a deep indentation into the center of each dough ball, place one frozen cookie butter scoop into the indentation, then seal the dough completely around it and roll back into a smooth ball. Press a few reserved white chocolate chips onto the top of each filled dough ball, if desired.

Cover the filled dough balls and refrigerate for 30 minutes.

Place dough balls on the prepared baking sheet about 1 inch apart. Bake for 12–15 minutes, until the edges are set and the tops are no longer shiny. Avoid over-baking.

Allow the cookies to cool on the baking sheet for at least 15 minutes, then transfer to a wire rack to cool completely.

If using, melt the vanilla melting wafers (or chopped almond bark) according to package instructions and drizzle over cooled cookies. Sprinkle with the crushed Biscoff cookies and any extra white chocolate chips.