Prepare a 13x9 inch pan by lining it with parchment paper. Spray the paper with non-stick spray or butter.

Place the chocolate sandwich cookies in a large zipper bag and crush into small pieces. Set aside.

Then, melt butter over medium heat in a large pot.

When the butter is melted, add the bag of marshmallows and stir until smooth and melted.

Remove from heat and add the Rice Krispies cereal and cookies. Stir until well mixed. TIP: if you use a buttered spatula it will make the process much easier.

Transfer the mixture to the prepared pan and press mixture until the cereal mixture reaches the edges of the pan. Place a sheet of wax paper on top to keep the mixture from sticking to your hands.

Allow to cool for at least 2 hours.

Slice into squares and enjoy!