Spray the inside of your pot as well as the baking dish with your non stick cooking spray.
Place the pot on low heat and add the milk chocolate chips. Stir slowly and do not stop until the chips have melted into a smooth mixture. This will take about 90 seconds. It is important that you continue to stir to prevent sticking or burning.
Transfer the milk chocolate mixture to the baking dish. Use a spatula to remove it all from the pot and spread it out evenly in the pan.
Sprinkle the Caramel M&Ms on top while the milk chocolate is still warm. You don’t want to crush the candies because the caramel center will break apart from the rest of the chocolate shell. Just toss them in whole.
Place the pan in the refrigerator for one hour. Make sure it is resting on an even surface.
After one hour your bark should be solid. Remove it and use the knife to pry it from the pan. It should come out as one sheet of candy.
Break apart and serve. To keep fresh, keep your bark in an airtight container or bag until you are ready to serve. You do not need to refrigerate it further.
Be sure to put your bark in the refrigerator to cool it quickly.