Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking pan.
In a saucepan, melt the butter over low heat.
Remove from heat and stir in the sugar, eggs, and vanilla.
Mix in the flour, cocoa, and salt until just combined.
Fold in chocolate chips if desired.
Pour the batter into the prepared baking pan.
Smooth the top with a spatula.
Bake for 25-30 minutes or until a toothpick inserted comes out with a few moist crumbs.
Let cool in the pan before cutting into squares.
Serve and enjoy your delicious brownies!