Serves six to eight.
8 ounces unsalted butter, plus additional for greasing the pan
4 ounces high-quality unsweetened chocolate (preferably Scharffen Berger)
2 large eggs
1 and 2/3 cups sugar
1 teaspoon vanilla
1 cup all-purpose flour
1/2 teaspoon salt
2/3 cup coarsely chopped pecans (or 1/3 cup pecans and 1/3 cup chocolate chips)
Preheat the oven to 350 degrees.
Melt the butter and chocolate in a bowl set over a saucepan of simmering water.
Beat the eggs, sugar, and vanilla together in a bowl until combined. Add the melted butter and chocolate, and whisk until incorporated. Fold in the flour and salt, and finally stir in the nuts.
Pour into a greased 9-by-9-inch pan and bake for approximately 35 minutes or until it's just pulling away from the sides; the center should be very moist but not runny.
Allow to cool in the pan before cutting. Best served when the brownies have rested for several hours.