Heat oven to 350 degrees. Spray a Whoopie Pie Pan with nonstick cooking spray.
Cut slices of cookie dough, about 1/2" thick. Press into each whoopie pie cavity of your pan.
Press the coarsely chopped Thin Mint cookies on top of the cookie dough.
Bake for about 8-10 minutes, until edges of cookies are slightly browned. Let cool completely before removing from pan.
Note: if you do not have a whoopie pie pan, you can use a pizza pan or a jelly roll pan. Press the entire tube of cookie dough into the large pan, then sprinkle with the chopped Thin Mints and press them into the dough. It will take longer to bake this way. Cool, then cut into slices.