Preheat oven to 350°F (175°C) and line an 8x8 pan with parchment paper.
Zest and juice the lemons, setting aside the zest and fresh juice separately.
In a mixing bowl, cream melted butter and granulated sugar until smooth.
Add eggs, lemon zest, lemon juice, vanilla extract, and salt to the mixture. Whisk until combined.
Gradually fold in the flour, mixing gently until just combined. Do not overmix.
Pour the batter evenly into the prepared pan and smooth the top with a spatula.
Bake for 20-25 minutes or until edges are set and the center is slightly firm.
Allow the brownies to cool completely in the pan before preparing the glaze.
For the glaze, mix powdered sugar with a small amount of lemon juice until smooth.
Spread the glaze evenly over the cooled brownies, then cut into squares to serve.
