Hi Christi;
Here's what you are looking for and it is very good.
Tunnel of Fudge Cake

Ingredients

Cake:
1 3/4 C softened butter or margarine
1 3/4 C granulated sugar
6 eggs
2 C powdered sugar
2 1/4 C all purpose flour
3/4 C unsweetened cocoa
2 cups chopped nuts

Glaze:
3/4 C powdered sugar
1/4 C unsweetened cocoa
1 1/2 to 2 T milk

Instructions
Heat oven to 350 degrees F. Grease and flour 12-cup fluted tube pan or 10-inch tube pan. In large bowl, beat margarine and granulated sugar until light and fluffy. Add eggs one at a time, beating well after each addition. Gradually add powdered sugar; blend well. By hand, stir remaining cake ingredients until well blended. Spoon batter into prepared pan; spread evenly. Bake at 350 degrees for 58 to 62 minutes. Cool uprigfht in pan on wire rack 1 hour; invert onto serving plate. Cool completely.
In small bowl, combine glaze ingredients until well blended. Spoon over top of cake, allowing some to run down sides. Store tightly covered. 16 Servings.