½ cup unsalted butter (1 stick)
1 cup granulated sugar
½ cup semisweet chocolate chips
2 large eggs
1 teaspoon vanilla
½ cup (47 grams) unsweetened cocoa powder
½ cup (64 grams) all-purpose flour
½ teaspoon kosher salt
1⁄8 teaspoon baking soda
½ cup chopped walnuts or pecans (optional)
cooking spray or shortening
Step 1
Heat the oven to 325 degrees, with a rack positioned in the center.
Grease an 8-inch-square baking pan with cooking spray or shortening and line the bottom with parchment paper.
Step 2
Combine the butter and sugar in a small saucepan. Cook over medium heat, stirring occasionally, until the butter comes to a simmer. Turn off the heat, then add the chocolate chips and stir until melted. (The mixture will be grainy at this point.) Pour into a large mixing bowl and set aside until just warm to the touch.
Step 3
Add the eggs and vanilla to the mixing bowl and whisk vigorously for 1 minute, until pale and glossy. Add the cocoa powder and whisk until incorporated. Add the flour, salt and baking soda and mix with a wooden spoon or spatula until well combined. If adding nuts, stir them in now. Transfer the batter to the prepared pan and smooth the top.
Step 4
Bake brownies until a toothpick comes out with just a few crumbs on it, 30 to 33 minutes.
For easy cutting, let the brownies cool completely and then use a hot, dry knife, wiping off the crumbs in between cuts.