1. Preheat oven to 325 degrees F. Butter a 9-inch pie pan or a 9- to 9 1/2-inch tart pan with a removable bottom.
2. Prepare crust. In a medium bowl mix together cookie crumbs, sugar, and melted butter. Transfer crumbs to prepared pan. With clean dry hands, press crumbs smoothly and evenly onto bottom and sides of pan. Chill for 10 minutes (this will help keep crust firmer) then bake at 325 degrees for 8 minutes. Let cool for 20 minutes before filling.
3. Prepare truffle filling. In a medium saucepan over low heat, heat cream and butter until butter melts and mixture is near boiling - watch carefully to make sure it doesn't burn. Turn off heat and add chocolate. Let sit for 1 to 2 inutes to melt chocolate, then whisk until smooth. Whisk in peppermint extract.
4. Scoop chocolate mixture into prepared crust and spread to edges. Refrigerate until firm, about 2 hours. To serve, carefully slide a small knife around edge of crust to loosen it. If you used a tart pan with removable sides, remove sides and transfer to a serving plate. If you used a pie pan, slice directly from pan. Garnish with fresh mint leaves, if desired. Use a sharp knife to cut slices. You can prepare the tart up to two days ahead of time.
5. Store in refrigerator and serve chilled.
Source: Hannaford fresh Magazine, November - December 2008