In a small saucepan, combine milk and butter. Cook and stir over low heat until butter is melted. Place the confectioners sugar in a large bowl; add milk mixture and beat until smooth. Stir in the walnuts, maple flavoring and vanilla. Roll into 3/4-in. balls; place on waxed paper-lined baking sheets. Refrigerate until firm, about 1 hour.

In a microwave, melt the chips, bittersweet chocolate and shortening; stir until smooth. Dip balls into chocolate; allow excess to drip off. Place on waxed paper; let stand until set. Store in an airtight container. Yield: about 13 dozen.

1 candy equals 67 calories, 3 g fat (1 g saturated fat), 2 mg cholesterol, 8 mg sodium, 10 g carbohydrate, trace fiber, 1 g protein.