How to Make It
Preheat the oven to 375°. Butter an 8-inch-square metal baking pan. In a saucepan, melt the chocolate with the butter over low heat. Let cool slightly.
In a medium bowl, beat the sugar with the eggs and vanilla. Add the melted chocolate and beat until smooth. Stir in the flour and salt, then fold in the nuts.
Scrape the batter into the prepared baking pan and bake for 25 minutes, or just until firm. Let cool completely in the pan. Cut into squares and serve.