Start by melting the unsalted butter in a medium saucepan over medium heat. Stir frequently as the butter melts, then begins to foam and turn golden brown. Once you see small brown flecks at the bottom of the pan and the smell is toasty, remove it from heat immediately to prevent burning. Set aside to cool slightly.
In a large mixing bowl, combine the sugar and eggs. Whisk vigorously until the mixture is smooth and slightly pale. Add the vanilla extract and the browned butter (make sure it’s warm, not hot, to avoid cooking the eggs). Mix until fully incorporated.
In a separate bowl, sift together the all-purpose flour, cocoa powder, salt, and baking powder. Sifting helps to avoid lumps and makes sure the cocoa and flour are evenly mixed.
Gradually fold the dry ingredients into the wet mixture using a spatula. Mix gently until just combined—overmixing can lead to tougher brownies. If you’re using chopped walnuts or pecans, fold them in at this point.
Preheat your oven to 350°F (175°C). Line your 8x8-inch baking pan with parchment paper or grease it lightly. Pour the batter into the prepared pan and spread it evenly. Bake for 30-35 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs but no wet batter. The edges should be set and slightly pulling away from the pan.
Allow the brownies to cool completely in the pan on a wire rack before cutting. This resting time helps them set and makes slicing cleaner. Cut into squares or fun bat wing shapes to embrace the spooky theme!
