Preheat oven to 350 degrees F. Well grease and flour a 10 inch Bundt pan. Cream butter at high speed. Add eggs one at a time, beating well after each addition. Add sugar gradually, creaming at high speed until light and fluffy. Gradually add flours. Stir in the frosting and nuts by hand until well blended. Pour into pan. Bake 50 - 69 minutes or until the cake pulls away from the sides of the pan and springs back when touched. Cool 1 hour on a rack and flip onto a platter.
Notes: This is not grainy if Asian or fine grained rice and tapioca flours are used. The butter flavor is a large part of this recipe, I would not suggest using margarine. If unable to find Duncan Hines Dark Chocolate Fudge Frosting, you can sub in another flavor, look for a dark and bold tasting frosting that will add a strong chocolate flavor. I have flipped this cake out after a shortened cooling time and been somewhat successful. Icing is optional.