½teaspoonsaltincrease to 1 if using unsalted butter
1cupchopped walnuts or pecans
Instructions
Preheat oven to 350 degrees F. Line a 9x13 inch pan with nonstick foil.
Melt 1 stick (4 oz) of the butter and chocolate in small saucepan over low heat or in the top of a double boiler; set aside to cool.
Place remaining (4 oz) stick of butter, sugar and vanilla in mixer bowl.
Using the the flat blade, beat on mixer speed 2 for about 30 seconds. Scrape side of bowl and increase speed to 6 and beat for 2 minutes. If the butter was still pretty cold, you might want to mix for another 2 minutes.
Decrease to mixer speed 4 and add eggs, one at a time, beating for 15 seconds after each egg, scraping bowl often.
Add cooled chocolate mixture and mix on Speed 2 for 30 seconds.
Stop and scrape bowl, then add salt and flour and stir on a low speed until blended. Stir in nuts, then pour into the pan an bake for 30 minutes (not 45, which is what the book says).
Let cool completely, then remove from the pan and cut into squares.
Notes
The original recipe gives a baking time of 45 minutes, but the correct time is more like 30 minutes. If you are unsure, check with a meat probe, but at 30 minutes I usually get over 212 degrees F.