Preheat the Oven: Set your oven to 350°F (175°C) and allow it to fully heat. Line an 8x8-inch metal baking pan with parchment paper.
Beat the Eggs and Sugar: In a stand mixer, combine the eggs, granulated sugar, and vanilla extract. Beat on medium speed for about 3-4 minutes.
Melt the Butter: In a saucepan over medium heat, melt the salted butter. Whisk in the icing sugar, cocoa powder, and salt.
Combine Cocoa Mixture with Eggs: Pour the warm cocoa mixture into the beaten eggs and sugar. Beat for about 30 seconds.
Add the Flour: Gently add the all-purpose flour into the batter. Mix until just combined.
Fold in Chocolate Chips: Incorporate the dark chocolate chips into the brownie batter gently.
Bake the Brownies: Pour the batter into the prepared baking pan and bake for 20-22 minutes.
Cool Completely: Let the brownies cool in the pan completely before cutting, refrigerate for at least 1 hour.