Prepare Baking Dish: Spray a 9x13 inch baking dish with nonstick cooking spray. Line it with wax paper, then lightly spray the wax paper as well.

Heat Condensed Milk: In a small nonstick pot, combine the condensed milk and peppermint extract. Heat this mixture over medium-low heat until it starts to steam and simmer (be careful not to let it boil).

Melt Chocolate Chips: Place the chocolate chips in a heat-safe bowl. Once the condensed milk mixture is hot, pour it over the chocolate chips.

Combine Mixture: Whisk the condensed milk and chocolate chips together until they are well combined and the mixture is smooth.

Transfer to Baking Dish: Pour the fudge mixture into the prepared baking dish, spreading it evenly.

Add Toppings: Sprinkle the chopped Mint Cookie Bark and Peppermint Bark evenly over the top of the fudge.

Cool the Fudge: Allow the fudge to cool completely at room temperature. For quicker cooling, you can place it in the refrigerator.

Cut into Squares: Once cooled, cut the fudge into squares and serve.