Pecan Fudge Sheet Cake

1 (18.25 ounce) box Duncan Hines Moist Deluxe Devil's Food Cake Mix
1/2 cup butter or margarine
1/4 cup plus 2 tablespoons milk
1/4 cup unsweetened cocoa
1 pound confectioners' sugar (3 1/2 to 4 cups)
1 teaspoon vanilla extract
3/4 cup chopped pecans

Heat oven to 350 degrees F. Grease a 15 1/2 x 10 1/2 x 1-inch jellyroll pan.

Prepare cake following package directions. Pour batter into pan. Bake for 20 to 25 minutes or until a wooden pick inserted in center comes out clean.

For frosting, combine butter, milk and cocoa in medium saucepan. Stir over low heat until butter is melted. Add confectioners' sugar and vanilla extract, stirring until smooth. Stir in pecans. Pour over warm cake. Cool completely.

Tip: For best results, allow the cake to cool undisturbed until frosting is set, about 4 hours.