PREP THE PAN: Line a quarter sheet pan with aluminum foil and spray with Pam (with flour). The foil makes it easier to lift the brownies out of the pan to cut.

MELT the chocolate with the butter, stirring occasionally, until the mixture is smooth, using a metal bowl set over a pan of barely simmering water. When melted, remove the bowl from the heat and let the chocolate cool to room temperature. Or, melt chocolate and butter in microwave at 50% power.

WHISK eggs until well beaten, in a large bowl. Stir in the sugar and vanilla.

ADD melted chocolate and butter; stir well.

MIX in the flour and salt, stirring with a whisk, until the mixture is just combined.

STIR in the chocolate chips and the nuts. Scrape the bottom and sides of bowl and mix in, using a rubber spatula.

POUR the batter into the pan and spread evenly, smoothing the top with an offset spatula.

BAKE in 350º F (177° C) oven 32-35 minutes total, or until a wooden skewer comes out with just a few moist crumbs adhering to it. Rotate pan after 20 minutes of baking. ( Don't allow to bake until tester comes out clean or the brownies will be over-baked and too dry.) Watch closely and test often towards the end of the baking time. Let cool in the pan.

CUT BROWNIES into 2" (5 cm) squares when cool. How you cut them depends on how perfect you want the brownies to look. You can cut them in the pan using the "eyeball" method for size (the most rustic look), or lift out with the foil and place on a cutting board to cut. If cutting in the pan, use a not-too-sharp dinner knife to prevent damaging the pan. The brownies can also be refrigerated and cut cold (a little less rustic). For a clean professional cut, with sharp edges, freeze before cutting, which is the technique I prefer. Lift frozen brownies out of the pan holding onto the foil, then cut into 2" wide strips (measured with a C-thru ruler) using a long thin slicing knife. Then cut crosswise in 2" strips, creating 2" squares. I know that sometimes you just can't wait for all of the chilling or freezing, so go ahead and dig in.

SERVE plain or dusted with powdered sugar.