Preheat the oven to 350°F (175°C). Line an 8×8 inch baking pan with parchment paper. This prevents brownies from sticking.
In a microwave-safe bowl, melt butter and chopped chocolate together. Stir every 30 seconds until smooth. You can also use a double boiler.
In a large bowl, whisk sugar and eggs together until combined. Add vanilla extract. This creates a smooth, sweet base for your brownies.
Pour melted chocolate mixture into the egg and sugar mixture. Stir gently until fully combined and glossy. Avoid overmixing.
Sift flour and salt into the mixture. Fold gently with a spatula until no flour streaks remain. Do not overmix to keep brownies fudgy.
Fold in chocolate chips or chopped nuts if desired. This adds texture and extra flavor to the brownies.
Pour the brownie batter into the prepared pan. Smooth the top with a spatula. Make sure it is even for uniform baking.
Bake in the oven for 25–30 minutes. Check with a toothpick; it should come out with a few moist crumbs, not completely dry.
Let brownies cool in the pan for 10–15 minutes. Lift using parchment paper and cut into squares. Serve warm or at room temperature.
