Preheat your oven to 350°F (175°C) and grease and flour an 8x8 inch baking pan. This ensures even baking and prevents sticking.

In a microwave-safe bowl or a small saucepan, melt the unsalted butter. Once melted, stir in the granulated sugar and unsweetened cocoa powder until well combined.

Whisk in the eggs one at a time, ensuring each is fully incorporated before adding the next. Stir in the vanilla extract.

Gently fold in the all-purpose flour and salt until just combined; be careful not to overmix, which can lead to tough brownies.

Pour the batter into the prepared baking pan and spread evenly. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out with moist crumbs, not wet batter.

Allow the brownies to cool completely in the pan before cutting them into squares. This helps them set and makes for cleaner cuts.