Begin by placing a large skillet over medium heat and adding in the unsalted butter. Continuously stir until fully melted, about 2-3 minutes.

Once the butter is melted, add the mini marshmallows to the skillet. Stir constantly for an additional 3-5 minutes until completely melted.

Remove the skillet from heat and stir in the zesty orange rind and freshly squeezed orange juice until well integrated.

Add the Rice Krispies cereal and dried cranberries to the melted marshmallow mixture. Gently fold together until well coated.

Prepare a 9x13 inch baking dish by spraying it with non-stick cooking spray. Spread the Rice Krispie mixture into the dish and pack it down firmly.

Allow the treats to cool completely at room temperature for about 30-45 minutes, then cut into squares or rectangles to serve.