Melt chocolate over hot water; set aside. Cream shortening and sugar thoroughly. Add eggs, one at a time, beating after each addition. Add sifted dry ingredients alternately with combined milk and vanilla. Beat until smooth after each addition. Mix melted chocolate with 1/2 of the batter. Pour 1/3 of the plain batter into greased and floured 9-cup Mini-Bundt pan. Pour half of chocolate batter on top of the plain. Repeat, finishing with plain batter. Cut a zig-zag pattern through the batter with a knife. Bake at 350 degrees for 35-40 min. Cool 15 min. before removing from pan. Sift confectioners' sugar lightly over top.