1. Preheat oven to 350°F. Place 12 liners in a muffin pan. Place one Mint Oreo in the bottom of each liner.
2. In a large bowl, using a rubber spatula or wooden spoon, combine the egg and sugar. Add the vanilla extract and melted butter and stir to combine. Add the flour, baking powder, and salt, and stir until just incorporated. Stir in the milk.
3. Divide the batter evenly between 12 muffin cups. Bake for 12­-14 minutes, until a toothpick inserted into the center of a cupcake comes out clean. Cool completely before frosting.

For the frosting

1. In the bowl of an electric mixer fitted with the paddle attachment, whip butter for 5 minutes on medium speed (I use “4” on my KitchenAid). Butter will become pale & creamy.
2. Add the powdered sugar, milk, and vanilla extract. Mix on low speed for 1 minute, and then on medium speed for 5 minutes. Add in crushed Oreos and mix to incorporate completely, about 1 minute.
3. Frost cooled cupcakes. If desired, top with half an Oreo or a mini Oreo to garnish.

For the ganache

1. Place the chocolate into a medium bowl. Heat the cream in a small sauce pan over medium heat. Bring just to a boil and then remove from heat and pour over the chocolate. Let sit for about 1 minute, and then whisk until smooth. Let cool for 15 minutes before pouring about 1 tablespoon over each frosted cupcake. Top with Oreo half.