Peppermint Patties

1 box confectioners' sugar -- (1pound)
3 tablespoons butter or margarine -- softened
2 or 3 tsp peppermint extract
1/2 teaspoon vanilla extract
1/4 cup evaporated milk
2 cups semisweet chocolate chips -- 12oz
2 tablespoons shortening I

In a bowl, combine first four ingredients. Add milk and mix well. Roll into 1-in. balls and place on a waxed paper-lined cookie sheet. Chill for 20 minutes. Flatten with a glass to 1/4 in.; chill for 30 minutes. In a double boiler or microwave-safe bowl, melt chocolate chips and shortening. Dip patties; place on waxed paper to harden and freeze for a short while. Yield: about 5 dozen.