This cake looked so good when I saw the picture, I thought I had to make it. Everyone I feed loves chocolate, so it was a no-brainer. Besides I love chocolate and mint together. I found the recipe on a blog called somethingswanky.com.
Prepare and bake the cake mix in a 9x13-in. 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 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. (I just crumbled the cookies across the cake and poured the hot fudge over the top.)
In a large bowl, whisk together the mint packet and the cool whip. spread the whipped topping over the fudge layer.
Crumble the remaining cookies over the top of the cool whip. Sprinkle the Andes Mint chips over top.
Refrigerate and chill for at least 4 hours (overnight is best).
Cut and serve.
NOTE: If you are like me, I had no idea what a Duncan Hines flavor packet was. I found that Duncan Hines makes several different flavor packets and I found them in the baking aisle near the cake mixes.