3 cups graham cracker crumbs
2 cups colored miniature marshmallows
1 cup walnuts or pecans, chopped
1 cup confectioners' sugar
2 cups semisweet chocolate chips
1 cup evaporated milk
1/2 teaspoon peppermint extract (optional)

In a large bowl, combine the crumbs, marshmallows, nuts and sugar.

In a saucepan, melt chocolate chips and milk over low heat, stirring often until blended and smooth. Remove from heat; add extract if desired. Set aside 1/2 cup. Pour remaining chocolate mixture over crumb mixture; stir until well blended. Pour batter into a greased 8-inch square baking pan. Press down evenly. Frost with reserved chocolate mixture. Chill for 1 hour.