For the cake:
Cream butter and sugar thoroughly; add eggs, one at a time, beating well after each addition. Sift flour and salt twice. Combine soda and buttermilk. Add flour alternately to the creamed mixture with the buttermilk, beginning and ending with the flour. Pour boiling water over the chocolate, stirring until smooth. Add to batter. Mix well and add vanilla. Pour into a well greased and floured 9x13 inch pan and back at 325 degrees for 50 – 60 minutes.

For the frosting:
Combine butter, chocolate and half & half in a saucepan; cook until butter and chocolate melt. Remove from heat and stir in sugar and whipping cream.