Start by preheating your oven to 350°F (175°C). This ensures that your cookies bake evenly.
In a large mixing bowl, use an electric mixer to cream together the room-temperature unsalted butter, light brown sugar, and granulated sugar until the mixture is light and fluffy.
Add in 1 cup of the Lotus cookie butter to the creamed mixture. Mix until fully incorporated.
Add the two large eggs, one egg yolk, and vanilla extract to the mixture. Beat well until everything is combined.
In a separate bowl, whisk together the all-purpose flour, baking soda, baking powder, and kosher salt. Gradually add this dry mixture to the wet ingredients, stirring until just combined.
Gently fold in the remaining white chocolate chips and the crushed Biscoff cookies, ensuring they are evenly distributed throughout the dough.
Use a cookie scoop to drop heaping tablespoons of dough onto lined baking sheets, spacing them about 2 inches apart. Bake in the preheated oven for 10-12 minutes, or until the edges are golden, and the center is still soft.
Once baked, let the cookies cool on the baking sheet for a few minutes before transferring them to a cooling rack. If desired, melt the vanilla melting wafers and drizzle over the cooled cookies for an extra touch of sweetness.
