Preheat your oven to 350°F (175°C) and prepare a 9x13 inch baking pan by lining it with parchment paper and lightly greasing it.

In a medium bowl, whisk together the all-purpose flour and salt until evenly combined. Set aside.

Cream together the softened unsalted butter and granulated sugar using an electric mixer on medium speed for about 3-4 minutes until light and fluffy.

One by one, add the large eggs into the creamed mixture, mixing well after each addition. Blend in the fresh lemon zest, lemon juice, and vanilla extract.

Gently fold the dry flour mixture into the wet ingredients until just combined, being cautious not to overmix.

Pour the batter into the prepared baking pan and spread it evenly. Bake for 25-30 minutes until edges are golden and center springs back.

Remove brownies from the oven and let cool completely in the pan on a wire rack for about an hour.

Prepare the lemon glaze by mixing powdered sugar with fresh lemon juice and lemon zest in a small bowl until smooth.

Once cooled, pour the lemon glaze over the brownies and let set for 30 minutes before cutting into squares.