Classic Brownies

5 Tbsp unsalted butter, cut into 5 pieces
4 oz bittersweet chocolate, coarsely chopped
2 oz unsweetened chocolate, coarsely chopped
3/4 c sugar
2 large eggs
1 tsp vanilla extract
1/2 tsp instant espresso powder ( optional)
1/4 to 1/2 tsp salt
1/3 c all purpose flour
1 c chopped walnuts

Get ready:
Center a rack in the oven
Preheat oven to 325
Line an 8" square pan with boil, butter foil, and place the pan on a baking sheet.

Set a heat proof bowl over a saucepan of simmering water. Put the butter in the bowl, top with the chopped chocolates and stir occasionally until the ingredients are just melted - you don't want them to get so hot that the butter separates. Remove the bowl from the pan of water.

With a whisk, stir in the sugar. Don't be concerned when your smooth mixture turns grainy. 1 by 1, whisk in the eggs. Add the vanilla and give the ingredients a vigorous whisking before gently stirring in the espresso, if you're using it, salt and flour; stir only until incorporated. Switch to a rubber spatula and fold in the chopped walnuts.

Scrape the butter into the pan, and smooth the top with the spatula.

Bake the brownies for 30 to 33 min, or until the top is dull and a thin knife inserted into the center comes out clean. Transfer the pan to a rack and cool the brownies to room temperature.

When the brownies are completely cool, turn onto a rack, peel away the foil and invert onto a cutting board. Cut into 16 squares.