Preheat your oven to 350°F (175°C) and grease or line an 8x8 inch baking pan.

In a large bowl, combine lemon juice, lemon zest, sugar, and melted butter until well mixed.

Add eggs to the mixture and beat until light and fluffy, ensuring no visible streaks of egg remain.

Sprinkle in flour and fold gently into the mixture until just combined to avoid overmixing.

Pour the batter into the prepared baking pan and smooth the top with a spatula.

Bake for 25-30 minutes and check for doneness with a toothpick; it should come out clean or with a few moist crumbs.

Allow the brownies to cool in the pan for 10-15 minutes, then transfer to a wire rack to cool completely before cutting into squares.