Let butter, eggs and milk stand at room temperature 30 minutes. Meanwhile, generously grease and flour two 8x8x2-inch loaf pans. Sift together flour, cocoa powder, baking powder and salt; set aside. In large bowl, beat butter and shortening with free-standing electric mixer on medium to high speed for 30 seconds. Gradually add sugars, beating about 10 minutes or until very light. Add vanilla. Add eggs, one at a time, beating 1 minute after each and scraping bowl frequently. Add flour mixture and milk alternately to beaten mixture, beating on low to medium speed after each addition just until combined. Pour batter into prepared pan. Bake in 325°F oven for 50 minutes. Then cover top very loosely with foil. Continue baking at 325° for 10 to 20 more minutes or until cake springs back to touch, sides pull away from pan, and long skewer inserted in center comes out with no wet batter.
Let cake cool 15 minutes, then remove from pans. Cook cake completely on wire rack. Cover tightly with aluminum foil. Let cake stand for 3 to 4 days before you ice it. Frost cake with Kahlua Icing. Makes 10 to 20 servings, depending on size of serving.
Kahlua Icing: In small saucepan melt 6 ounces of chopped, semisweet chocolate over low heat; cool slightly. In medium mixing bowl beat together 1 cup softened butter, 2 1/2 cups powdered sugar and 1/4 cup Kahlua® until light and fluffy. Beat in melted chocolate. Ice top and sides of cake. You can decorate cake’s border with chocolate covered espresso beans.