In heavy saucepan over low heat, melt candy bars with 1 stick of the butter, stirring frequently until smooth. Remove from heat and allow to cool. Beat remaining stick of butter and sugar until light and fluffy. Add eggs one at a time, mixing well after each addition. Stir together flour and baking soda and add to butter alternately with buttermilk, mixing just until dry ingredients are moistened. Blend in cooled Milky Way mixture, vanilla and nuts. Turn into greased and floured Bundt pan or 25 cm tube pan. Bake in 180ºC . oven 1 hour and 20 minutes, or until top springs back when touched lightly and wooden pick inserted in center comes out clean. (Top will be quite dark.) Cool 10 minutes before removing from pan and cooling on wire rack.