01 -
Preheat oven to 350°F and grease a 9x13-inch pan with baking spray.
02 -
In a large mixing bowl, combine the brownie mix, eggs, melted butter, and milk. Mix until smooth, about 1-2 minutes, then fold in the chocolate chips.
03 -
Spread half of the batter (about 2 cups) evenly in the prepared pan.
04 -
Dollop spoonfuls of the cookie butter on top of the batter, then gently spread it to create an even layer.
05 -
Carefully spoon the remaining brownie batter over the cookie butter layer, starting from the edges and working toward the center. Smooth the top layer gently.
06 -
Sprinkle the chopped Biscoff cookies over the top.
07 -
Bake for 33-38 minutes, or until a toothpick inserted near the center comes out with a few moist crumbs.
08 -
Cool completely before cutting into squares and serving.