Preheat the oven

• Preheat the oven to 180 °C.

Make the batter

• Whisk the softened butter with the sugar until creamy.
• Add the lemon zest, lemon juice and eggs, then mix well.
• Fold in the flour, salt and baking powder until just combined.

Bake the blondies

• Pour the batter into a lined baking dish and spread evenly.
• Bake until golden and a skewer comes out clean.

Prepare the lemon topping

• Mix the icing sugar with the lemon zest and lemon juice until smooth.

Finish and serve

• Spread the lemon topping over the cooled blondies.
• Cut into squares and serve.