I Finally Found the Secret Ingredient to the Fudgiest Brownies Ever

Gather all ingredients. Position a rack in the top third of the oven and preheat to 350°F (175°C). (5 minutes)

In a medium saucepan over medium heat, melt the butter. Once melted and bubbling, add the granulated sugar. Cook, stirring constantly, until the sugar has completely dissolved, about 45 seconds.

Remove the saucepan from the heat and stir in the sweetened condensed milk and 1 cup of the dark chocolate chips. Continue stirring until the mixture is smooth and glossy, about 1 minute. Pour into a large, heat-proof bowl and allow to cool slightly, about 2 minutes.

While the chocolate mixture cools, prepare an 8-inch square baking pan by spraying it with cooking spray. Line the pan with parchment paper, leaving a slight overhang on all sides for easy removal. Lightly spray the parchment paper with cooking spray.

Add one egg to the warm, melted chocolate mixture and whisk vigorously to ensure it tempers properly and doesn't scramble. Whisk for approximately 20 seconds until fully incorporated. Repeat with the remaining egg, whisking until fully incorporated. Stir in the vanilla extract.

Add the all-purpose flour, Dutch-process cocoa powder, and kosher salt to the batter. Gently stir to combine using a rubber spatula. Fold in the remaining 1/3 cup of dark chocolate chips.

Pour the brownie batter into the prepared baking pan and spread evenly. Place the pan on the upper third rack of the preheated oven.

Bake until the brownies appear to be just set, the top is slightly shiny but not wet to the touch, and a wooden pick inserted into the center comes out mostly clean, about 40 to 45 minutes. Sprinkle with flaky sea salt, if desired, after 30 minutes of baking.

Remove the pan from the oven and place it on a wire rack to cool completely for 1 hour.

Use the overhanging parchment paper to lift the brownies out of the pan and transfer them to a cutting board. Cut into 9 equal squares. Serve warm or at room temperature, and savor the intensely fudgy goodness.