Preheat oven to 350 degrees F. Coat an 8- or 9-inch square
baking dish with nonstick cooking spray.
Combine the flour, sugar, cocoa powder, brown sugar, baking
powder and salt in a large mixing bowl. Set aside.
Place half of the bittersweet chocolate and the milk in a small
saucepan and place it over LOW heat. Cook and stir for a minute
or two and then add the butter. Continue cooking over LOW heat,
stirring constantly, until the butter and chocolate have
completely melted. Remove the pan from the heat and stir in the
vanilla.
Pour the melted chocolate mixture into the flour mixture in the
mixing bowl and stir until slightly combined. Add the eggs,
remaining bittersweet chocolate, and ¼ cup of the walnuts
(reserve remaining nuts for later) to the flour mixture and stir
to combine.
Pour the batter into the prepared baking dish and sprinkle with
the remaining ¼ cup walnuts.
Bake until a wooden pick inserted in the center comes out with
moist crumbs clinging, approximately 20 to 22 minutes for 9-inch
baking dish or 22 to 26 minutes for a 8-inch baking dish. The
edges should seem solid but the center will appear somewhat soft
and will continue to set up as the brownies cool. Ovens can vary
so I recommend setting your kitchen timer for a couple of
minutes shy of the recommended baking times and watching them
closely towards the end. Remove from the oven and cool
completely in the baking dish before cutting and serving.
NOTE:
Substitute for one ounce of bittersweet chocolate is one ounce of
unsweetened chocolate and two spoons sugar.
