1. Melt together butter unsweetened chocolate and take the saucepan off the heat.
2. Stir in sugar, eggs and vanilla, and beat the mixture well.
3. Stir in flour and salt. You may also add walnuts at this point.
4. Bake the brownies in a buttered and floured 20 cm-square pan at 160ºC . for about 40 minutes.
This from Laurie Colwin's *More Home Cooking: A Writer Returns to the Kitchen.* She writes that it is, apparently, the Hepburn family recipe.