Prepare and bake the cake mix in a 9x13 baking dish. Allow to cool completely.
Use the bottom of a wooden spoon to poke holes evenly across the entire cake (about 20 holes). Pour the can of sweetened condensed milk over the cake, trying to fill the holes.
Heat the hot fudge sauce in a small bowl in the microwave. 30-40 seconds should do the trick, you just want it to soften a little.
Crumble half of the fudge mint cookies into the hot fudge sauce and mix. Spread the cookie/fudge sauce over the cake.
In a large bowl, whisk together the mint extract, food coloring and the whipped topping. Spread the whipped topping over the fudge layer.
Crumble the remaining cookie crumbs over top of the whopped topping. Sprinkle the mint chips over the top.
Refrigerate and chill for at least 4 hours, overnight is best.