Prepare cake mix with oil, eggs, peppermint extract, water and sour cream. Mix well. Add pudding mix at the last. Using a large ziploc bag, coarsely crush up about 1 cup of the cookies and add to batter. Scoop into papered cupcake pans 2/3 full. Bake 350 about 12 min or until toothpick comes out clean.
Place the white frosting in mixer, adding green food color and powdered sugar to desired green tint and consistency. Fit a piping bag with your desired tip and place the green inside on one half and chocolate frosting in on the other half side to create a swirled effect when piping out the frosting. Frost cupcakes.
Take about 8 cookies and carefully cut them into quarters. Maybe a few extra in case they crumble too much. Place a quartered cookie on each cupcake, slightly pushing into frosting so as not to fall off.
Place the candies in a small ziploc bag and crush coarsely with a rolling pin or hammer or whatever you have that works. Sprinkle over top of cupcakes while frosting is still soft and wet. They wont stick if they sit too long.
You can also make minis. I found some mini York peppermint patties and placed those atop, omitting the crushed oreos in the batter.