Prepare an 8x8 pan. Line it with aluminum foil and then liberally spray the aluminum foil with cooking spray.
Divide the condensed milk into 2 separate microwavable bowls. (It should be 1/2 cup of the condensed milk in each bowl.
Add 1 cup of dark chocolate chips to one of the bowls, and 1 cup of white chocolate chips to the other bowl.
Microwave the bowl with the dark chocolate/condensed milk mixture first. Microwave for 30 seconds, stir, then 30 seconds again. Add in 1/4 teaspoon of peppermint extract.
Stir and then spread evenly in the prepared pan.
Add your candy canes to a zip-top bag, seal the bag, then crush them. I just bang the bag on the counter but you could use a rolling pin or a meat mallet too. Set aside 2 tablespoons of the crushed candy for the topping.
Microwave the other bowl of condensed milk and white chocolate chips. Again, microwave for 30 seconds, stir, then 30 seconds again.
Add in 1/4 teaspoon of the peppermint extract and the crushed peppermints. Stir to combine.
Pour the white chocolate mixture over the dark chocolate and spread evenly. Immediately top with the reserved crushed candy canes.
Refrigerate for 2 hours then you can lift the foil out and discard. Slice the fudge into bite size piece and enjoy!