Preheat the oven to 350ºF. In a medium bowl, whisk the flour, cocoa powder, baking soda, and salt together until combined; set aside.

In the bowl of an electric stand mixer fitted with a paddle attachment, cream the butter until smooth. Add both sugars and mix on high for 2 minutes until light and fluffy. Add the eggs one at a time, mixing after each addition until combined. Add the vanilla. Then stir in the pudding mix.

With mixer set on low speed, slowly add the flour mixture into the wet mixture until everything has been incorporated. Stir in the Andes Mints.

Press half of the dough into a greased 10-inch cast iron skillet. Top the dough with a layer of Oreos. Evenly space Junior Mints on top of the Oreos.

Take chunks of the remaining dough, flatten slightly, and layer them side by side on top of the Oreos and Junior Mints.

Bake for 20-23 minutes, or until the center appears set. Allow to cool for 20-30 minutes. Serve slices with a scoop of ice cream, if desired.