Chocolate Mint Parfait Bars

1 (18.25 ounce) box chocolate devil's food cake mix with pudding
1/3 cup butter, softened
1 egg
1 envelope unflavored gelatine
1/4 cup boiling water
4 cups confectioners' sugar, divided
1/2 cup butter, softened
1/2 cup shortening
1/4 teaspoon peppermint extract
3 drops green food coloring
6 ounces chocolate chips
3 tablespoons butter

Heat oven to 350 degrees F. Grease 15 x 10-inch baking pan.

In large bowl, combine cake mix, 1/3 cup butter and egg. Beat at low speed until crumbly. Press evenly in bottom of greased pan. Bake for 10 minutes. Cool completely.

In a large bowl, dissolve gelatine in boiling water; cool slightly. Add 2 cups of the confectioners' sugar; blend well. Add 1/2 cup butter, shortening, peppermint extract and food color. Beat 1 minute at medium speed or until smooth and creamy. Blend in remaining 2 cups powdered sugar until smooth. Spread filling evenly over cooled base.

In small saucepan over low heat, melt frosting ingredients: chocolate chips and 3 teaspoons butter. Stir constantly until well blended.

Spoon frosting evenly over filling, carefully spreading to cover. Refrigerate until firm. Cut into bars. Let stand at room temperature about 20 minutes before serving. Store any remaining bars in refrigerator.

Makes 48 bars.

Source: 1982 Pillsbury Bake-Off Contest