In a small saucepan, mix together the butter and chocolate, stirring occasionally. Let the mixture cool before using.
Preheat the oven to 350 F. Butter a 13 x 9 x 2 in baking pan(for fudgy brownies) or a
9 x 9 x 2 in pan(for cakelike brownies).
In a medium bowl, beat together the eggs and salt until light and foamy, about 3 minutes. Beat in the butter mixture until blended. Then beat in the sugar and vanilla until well mixed. With a rubber spatula, fold in the flour and pecans. Scrap into the prepared pan.
Bake the fudgy pan for about 30 minutes, or the cakelike version for 40 minutes. Transfer the pan to a wire rack to cool. Cover and refrigerate until chilled, then cut into squares and serve.