Combine butter and shortening, mixing well; gradually add sugar, beating until light and fluffy. Add eggs, one at a time, beating well after each addition. Combine flour, cocoa, and baking powder - sift together. Add to creamed mixture alternately with the milk, beginnning and ending with flour mixture. Mix well after each addition. Add vanilla to mixture.

Pour batter into a well-greased 10-inch tube pan. Sprinkle pecans evenly over batter. Bake at 325 degrees for 1 hour and 15 minutes or until cake test done. Cool in pan 15 minutes; remove from pan, and let cake cool completely. Yield: one 10-inch cake.