Orange Chocolate Marble Cake with Chocolate or Orange Glaze
Source: NordicWare

1 cup butter or margarine
1 1/2 cups sugar
4 eggs, separated
2-1/2 cups sifted flour
2 tsp. baking powder
1/4 tsp. salt
2/3 cup milk
1/4 tsp. grated orange peel
1/4 tsp. orange extract
1/4 cup cocoa
1/4 cup water

Chocolate Glaze Topping:
2 cups sifted confectioners' sugar
1/4 cup cocoa
1 tbsp. soft butter or margarine
1/2 tsp. vanilla
2-4 tsp. milk

Orange Glaze Topping:
2 Cups sifted confectioners' sugar
1 tbsp. soft butter or margarine
2-4 tbsp. orange juice
1-2 tsp. grated orange peel

Cream butter or margarine; add sugar gradually, beating until fluffy. Beat in egg yolks, one at a time, until light and fluffy. Add sifted flour, baking powder, and salt, a third at a time, alternately with milk until blended. Fold in stiffly beaten egg whites.

Spoon 1/2 of batter into a second bowl; stir in orange peel and orange extract.

Blend cocoa and water in a cup: Fold into batter in first bowl.

Spoon batters, alternating layers of chocolate and white, at least 2 times, into greased Bundt Pan.

Bake at 350 degrees for 50- 60 minutes or until cakes tests done. Cool in pan 10-15 minutes; turn on wire rack or serving plate to complete cooling.

Top with Chocolate Glaze:
In small bowl, combine sugar, cocoa, and butter. Add vanilla; add milk gradually to achieve desired consistency and stir until smooth.

OR

Orange Glaze:
In small bowl, combine sugar and butter. Add orange juice gradually to achieve desired consistency and stir until smooth. Add peel.