Preheat your oven to 350°F (175°C).
Line a 9x13-inch baking pan with parchment paper.
In a large mixing bowl, combine melted butter and brown sugar. Mix until smooth. Add vanilla and mix again.
Add oats, baking soda, and flour to the wet mixture. Stir until just combined.
Fold in the Biscoff spread until evenly distributed.
Stir in the chocolate chips until incorporated.
Pour the batter into the prepared baking pan and spread evenly. Bake for 20-25 minutes.
Let cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.
