These brownies are rich, fudgy, and packed with chocolate and walnut goodness.
Preheat your oven to 350°F (175°C) and position the rack in the middle.
Preheating ensures even baking from the start.
Grease a 13 x 9-inch baking pan with butter and dust with flour, or line it with parchment paper.
Lining with parchment paper makes it easier to remove the brownies.
Melt the dark chocolate and butter together in a saucepan over low heat, stirring until smooth.
Use low heat to prevent the chocolate from burning.
Allow the melted mixture to cool slightly, then whisk in the sugar, vanilla, and eggs one at a time.
Adding eggs one at a time ensures a smooth batter.
Gently fold in the salt and flour until just combined, being careful not to overmix.
Overmixing can make the brownies dense.
Stir in the chocolate chips and chopped walnuts.
Coating mix-ins in a bit of flour prevents them from sinking.
Pour the batter into the prepared pan and spread it evenly.
Tap the pan gently to remove air bubbles.
Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
Avoid overbaking for fudgy brownies.
Let the brownies cool completely in the pan on a cooling rack before cutting into squares.
Cooling completely makes cutting easier and prevents crumbling.