Place the chopped strawberries in a medium bowl. Sprinkle with 2 teaspoons of sugar and mix well. Let stand for 30-45 minutes, then drain the excess juices.

Meanwhile, preheat the oven to 350ºF (180ºC). Line an 8-inch square baking pan with parchment paper, leaving a couple of inches of overhang to serve as handles to lift the blondies out of the pan.

In a separate medium-size bowl, whisk together the flour, baking powder and salt until well combined.

In a large bowl, whisk together the remaining 1/4 cup (50g) of sugar, the brown sugar, melted butter and vanilla until smooth. Add the egg and the egg yolk and whisk until smooth and well combined, about 2-3 minutes. Stir in the flour mixture, just until combined. Fold in the white chocolate chips and the strawberries.

Transfer the batter to the prepared baking pan. Bake until the top looks golden brown all over and a toothpick inserted into the center of the blondies comes out with a few moist crumbs on it, about 28-33 minutes. Let cool completely in the pan.

Remove the cooled blondies from the pan and cut into squares.

Finely chop, then mash the strawberries. Press the mashed strawberries through a sieve, using the back of a spoon or press the strawberries through a food mill. Whisk together the strawberries, powdered sugar, melted butter, lemon juice and salt until smooth. Drizzle over the cooled brownies.