Coffee-Orange Fudge Cake

1 devil's food OR German chocolate cake mix -- (18 1/4 ounce )
1 container sour cream -- (8 ounce)
1/2 cup vegetable oil
1/2 cup water
4 eggs
1 package instant chocolate fudge pudding mix -- (4-serving-size)
1/4 cup coffee liqueur
2 tablespoons finely shredded orange peel
1 teaspoon ground cinnamon
2 cups semisweet chocolate pieces
Confectioners' sugar

Preheat oven to 350 . Grease and flour a 10-inch fluted tube pan; set aside.

In large mixing bowl, combine cake mix, sour cream, oil, water, eggs, pudding mix, liqueur, orange peel and cinnamon. Scraping sides of bowl constantly, beat with an electric mixer on low speed until blended. Beat on medium speed for 4 minutes. Stir in chocolate pieces.

Pour into prepared pan. Bake in preheated oven until a toothpick inserted near center comes out clean, 50 to 60 minutes. Cool on wire rack for 10 minutes. Invert onto rack to cool thoroughly. Sprinkle with confectioner's sugar.