Preheat the oven to 350 degrees F. Line 24 muffin cups with liners.
For the crust: In a small bowl, stir together the crushed cookies and butter until combined. Divide among the prepared cupcake cups. Using a small juice glass or your fingers, press the crumbs into the bottom of the cupcake liners. Bake until fragrant, about 8 minutes. Set aside to cool completely.
For the cupcakes: In a large bowl, whisk together the sugar, flour, cocoa, baking powder, baking soda and salt. Add the eggs, milk, oil and vanilla and, using a hand mixer, beat on medium speed, 2 minutes. Stir in the boiling water. Pour the batter into the prepared cupcake liners (about 3/4 full). Bake until a wooden pick inserted in the center comes out clean, 17 to 20 minutes. Cool 10 minutes in the pan. Remove the cupcakes from the tins and transfer to a wire rack to cool completely.
For the buttercream: Meanwhile, in the bowl of an electric mixer, beat the butter until light and fluffy. Gradually add the confectioners' sugar until combined. Stir in the salt, mint extract and, if using, food coloring. Beat until creamy, about 2 minutes. Transfer the buttercream to a pastry bag fitted with a medium round tip.
Using an apple corer, remove the center of the cupcake down to the cookie crust. Fill the cupcakes with buttercream and smooth the tops with an offset spatula. Set aside. For the ganache: Place the chocolate in a medium bowl. In a medium saucepan, heat the butter and heavy cream until steaming (do not boil). Add the extract. Pour the hot cream over the chocolate and let stand 3 minutes. Using a rubber spatula, stir until smooth. Let cool slightly, about 5 minutes.
Dip the tops of the cupcakes into the melted chocolate (dipping until the chocolate meets the liner). Let the cupcakes set on a wire rack before serving, about 1 hour.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.