Line a 20 cm (8 inch) or 22cm (9 inch) square cake tin with baking paper and preheat oven to 180 °C (350 °F).
Place the butter and sugar into a large mixing bowl and stir till combined.
Mix in the eggs one at a time until just combined – do not overmix.
Add lemon juice, lemon zest, salt, and flour and stir to combine.
Transfer the batter to the prepared tin and smooth the top.
Bake for 20 -25 minutes or until lightly golden and a cake tester/toothpick inserted into the middle comes out clean.
Allow to cool completely before icing.
To make icing:
Combine the icing sugar and lemon juice in a small bowl until smooth and spreadable. If too thick add more lemon juice 1 -2 drops at a time, if too runny add more icing sugar 1 tablespoon at a time.
Spread over uncut brownies and top with lemon zest.
Allow the icing to set for a few minutes and then slice and serve.
Nutrition
Serving Size: 59g | Calories: 217 | Sugar: 23g | Sodium: 110mg | Fat: 8.8g | Saturated Fat: 5.4g | Trans Fat: 0.3g | Carbohydrates: 33g | Fiber: 1g | Protein: 2g | Cholesterol: 45mg