Place chocolate in top of a double boiler, bring water to a boil. reduce heat to low, cook until chocolate melts.
Cream shortening; gradually add sugar beating well at medium speed with an electric mixer. Add eggs, one at a time, beating well after each addition. Add chocolate mixing well.
Combine four, baking powder, soda and salt, add to chocolate mixture alternately with buttermilk, begin and end with flour.Mix after each addition. Add water, nixing well. Stir in vanilla.
Pour batter into 2 greased and floured 9 inch round cake pans. bake at 350F for 30 minutes or until wooed pick inserted in middle comes out clean. Cool in pans 10 minutes, remove from pans, and cool completely on wire racks.