Prepare your oven by preheating it to 325°F (163°C) convection. Lightly grease an 8x8-inch baking pan with baking spray, then line it with parchment paper, leaving an overhang for easy removal.

In a heatproof bowl, combine the salted butter and chocolate chips. Microwave the mixture for one minute, then stir thoroughly until the butter and chocolate are completely melted and smooth.

In a separate large bowl, whisk together the granulated sugar, light brown sugar, cocoa powder, eggs, and vanilla extract. Whisk vigorously for 2-3 minutes until the mixture becomes silky and smooth.

Slowly pour the melted chocolate and butter mixture into the bowl with the sugar and eggs. Stir well until everything is fully incorporated and the batter is glossy.

Sift in the all-purpose flour and fine sea salt. Gently fold the dry ingredients into the batter, being cautious not to overmix. Stop stirring as soon as only small streaks of flour remain visible.

Transfer the batter to the prepared pan, spreading it evenly to ensure a uniform bake. Place the pan in the oven and bake for 40-45 minutes. The brownies should develop a thin, crackly top and puff slightly in the center.

Once baked, tap the pan lightly against the counter to release any trapped air. The brownies should deflate slightly but feel soft underneath when pressed, with no jiggling.

Let the brownies cool in the pan for 30-60 minutes. Sprinkle a pinch of flaky sea salt over the top before serving. These fudgy brownies can be enjoyed warm or at room temperature.