Preheat oven to 175 C. Grease baking dish with butter.
Zest and juice 1 large lemon.
In the bowl beat the flour, sugar, salt, and softened butter electric mixture fitted with the paddle attachment, until combined.
In a separate bowl, whisk together the eggs, lemon zest, and lemon juice until combined. Pour into the flour mixture and beat increasing speed from low to high until smooth and creamy.

Pour into baking dish and bake for 25-30 minutes, until just starting to turn golden and a toothpick inserted into the center comes out clean. Allow to cool completely before glazing.
Whisk together the powdered sugar, lemon zest and juice. Spread the glaze over the brownies. Let glaze set for one hour.

Video with preparing is here: https://youtu.be/wuKqpUs9zDs?sub_confirmation=1