1 cup evaporated milk
2 cups miniature marshmallows
1 cup semisweet chocolate chips
1/3 cup sugar
1/8 teaspoon salt
1 tablespoon vanilla extract
1 tablespoons butter
3 cups Thin Mint cookies, crushed into crumbs
½ cup nuts, chopped

Mix together milk, marshmallows, chocolate chips, sugar and salt in microwaveable bowl. Bring to a boil in microwave. Stir well and cook in microwave an additional two minutes at medium high heat. Remove from microwave. Add butter, vanilla, and chopped nuts. Break Thin Mint cookies into crumbs and add to mixture. Pack into a 9-inch square pan. Refrigerate until hard. Cut into two-inch squares.

From http://www.girlscoutsww.org/cookies/recipes#Thin%20Mints