Pre-heat oven to 350 degrees. If using a stand mixer, fit with paddle attachment.
Prepare a muffin pan by placing cupcake wrappers into each hole. Place a chocolate sandwich cookie into each cupcake wrapper.
In a large bowl, mix together chocolate cake mix, Greek yogurt, water, and eggs. Beat on high speed for about 2 minutes. The batter will be thick.
Place a tablespoonful of batter into each prepared cupcake wrapper.
Bake at 350 degrees for 18-20 minutes. Allow to cool. I like to remove my cupcakes from the muffin pan and cool them on a cooling rack. I think that it makes the bottoms a bit soggy when you leave them in the pan to cool.
Frost as desired.