Gather all ingredients. Preheat the oven to 350 degrees F (175 degrees C). Grease an 8-inch square baking pan. Beat flour, white sugar, butter, and salt together in a large bowl using an electric mixer until well mixed. Whisk eggs, 2 tbsp lemon juice, and 1 tbsp lemon zest together in a separate bowl. Pour egg mixture into flour mixture; beat on medium speed with an electric mixer until smooth, about 3 minutes. Pour batter into the prepared baking pan. Bake in the preheated oven until a toothpick inserted in the centre comes out clean, 23 to 25 minutes. Cool on a wire rack until the bottom of the pan is warm to the touch. Meanwhile, make the lemon glaze: Whisk confectioners’ sugar, 1/4 cup lemon juice, vanilla extract, and lemon zest together in a bowl until smooth. Spread glaze over cooled brownies. Cut into squares. Yields 16 servings.