Butter or grease a 13x9" baking dish. Melt butter with marshmallows in a large non-stick pot. Add biscoff spread & stir to combine.

Remove from heat & add the rice krispies cereal. Stir to coat & press into the greased baking dish. Allow to cool slightly. Melt a couple tablespoons of biscoff spread in the microwave for 10 seconds & spread or drizzle it over the top of the treats. Allow to cool completely before cutting & serving.