Preheat oven to 350 degrees. Line a 13x9" pan with foil and spray with cooking spray.
Combine your cake mix, butter and egg in a large bowl. Mix well until dough forms - you may need to use your hands to really work dough together, it will be very thick. Press into the bottom of your lined pan.
Sprinkle half of the chocolate chips and peppermint chips onto your cake batter dough.
Pour can of sweetened condensed milk over the dough and chips.
Sprinkle remaining chips on top.
Bake for approx 25 minutes.
Remove from oven and let cool.
Mix Frosting Creations base with Frosting Creations Peppermint Stick Flavor Packet. Drizzle over bars. Sprinkle with crushed candy canes if desired.
Cut and serve.