Preheat the oven to 350F. Melt 4 ounces of the chocolate and 1/2 cup of the butter in the top of a double boiler over barely simmering water. In a mixing bowl beat together the eggs, sugar and flour. Pour the melted chocolate mixture into the egg mixture and mix well, beating hard until the mixture reaches the ribbon stage. Pour the mixture into a greased 8 or 9-inch cake pan and bake for 25 minutes, until a knife inserted in the center comes out clean. Cool on a rack for 10 minutes, then remove from the pan and cool completely. To make the frosting, melt the remaining chocolate and butter in the top of a double boiler over barely simmering water. Bring the cream to a boil in a small saucepan. Pour the hot cream into the chocolate mixture and stir to mix well. Pour the icing over the pie, spreading it evenly with a spatula. When the icing has hardened slightly, make a diamond pattern on top of the pie, using the back of a chef╒s knife. Sprinkle the pie with the cocoa.
