Preheat the oven to 180°c (160 fan/ Gas 4/ 350F) and line a 20cm square baking tin with baking paper.
Mix together the cooled melted butter and sugars until combined.
120 g Unsalted Butter, 100 g Granulated Sugar, 50 g Light Brown Sugar
Beat in the egg.
1 Egg
Fold in the flour, salt and baking powder.
130 g Plain Flour, ½ teaspoon Baking Powder, ¼ teaspoon Salt
Stir through the blueberries, lemon zest and white chocolate chunks.
1 Lemon, 100 g Blueberries, 100 g White Chocolate Chips
Spoon the blondie batter into the tin and bake for 22-25 minutes. The blondies should be just pulling away from the edge of the tin but soft in the middle.
Allow to cool fully before drizzling over the white chocolate icing. Leave to set before cutting into squares.
50 g White Chocolate