Preheat the oven 15-20 minutes to 350 degrees, grease and flour three 8×2 inch round pans, adding a circle of parchment paper in the bottom of each pan.

Place Oreos in a ziploc bag or between two sheets of waxed paper and crush with a rolling pin.

In a medium bowl, whisk the flour, baking powder, baking soda and salt for 30 seconds. Set aside

In another bowl, add the buttermilk, oil, vanilla and peppermint extract.  Set aside..

In the bowl of your mixer, add the butter and mix at medium speed until smooth. Gradually add the sugar and continue to mix on medium speed for 3 to 5 minutes until lightened in color and fluffy. Add the eggs one at a time mixing until the yellow of the yolk disappears.

Alternately add the flour mixture and buttermilk mixture, beginning and ending with the dry ingredients (3 additions of dry ingredients and 2 of liquid).

Add green coloring gel if you'd like.

Do not mix above medium speed or over mix the cake batter.

Fold in the crushed Mint Oreos. Divide batter between your pans.

Bake at 350 degrees for 25-30 minutes or until a toothpick inserted in the center comes out clean or with just few crumbs attached. *If baking in 9 inch pans, bake 25-30 minutes. Let cool 10 minutes and turn out.

This recipe makes 8 cups of batter

Place your chocolate into a microwave safe bowl.

Pour heavy cream over the chocolate and place in the microwave for 1 minute. (Times may vary, see our note below).

Remove and stir. Microwave for 30 seconds more if needed and when the chocolate has melted almost completely, allow it to sit for 1 minute more before stirring. Stir until you've reached a silky smooth consistency.

*Microwave times may vary. If you are making a smaller amount of ganache, you will reduce the microwave time. If your chocolate hasn't melted after the 1 ½ minutes recommended in the instructions, simply microwave in small 10-15 second increments until it has nearly completely melted. Let sit one minute, then stir until smooth.

Cream the (slightly softened) unsweetened butter until smooth.

Blend in the peppermint extract.

Add half of the powdered sugar and most of the milk. Beat at medium speed until the powdered sugar is incorporated.

Add remaining powdered sugar and milk and mix at medium speed another 3 to 4 minutes scraping the sides of the bowl occasionally. I slow down the mixer to very slow. (#2 on the Kitchenaid) for 1 to 2 minutes. This will help eliminate air pockets in the buttercream. The texture will become very smooth.

If your buttercream is too thin, add more powdered sugar. If the consistency is too thick, add a bit more milk.

Place the first cake layer on the pedestal or cake plate.
Spread with a layer of mint buttercream frosting, and then drizzle ganache on
top of that, along with additional crushed Mint Oreos. 

Repeat for the next cake layer, and top with the third cake layer. Crumb coat the cake with Mint Buttercream. (At this point I like to chill the cake in the freezer for 10-15 minutes).

Apply the second coat of frosting, smooth with bench warm metal scraper (or
your preferred method), and chill for 5-10 minutes more. 

Apply the ganache drip around the top edge of the cake, using a piping bag
with the very tip snipped away. (Ganache should not be hot).

After applying the drip all the way around, spread additional ganache on top
of the cake.

I added half of a mint Oreo to the center of the cake for decoration, and added a small
bead border piped with a small round tip 3 around the bottom of the cake.