Preheat your oven to 160℃ (or 140℃ if you're using a fan oven). Line an 8x8-inch tin with baking paper.
In a large bowl, mix together the melted butter, caster sugar and light brown sugar.
Stir in the eggs, lemon extract and vanilla extract.
Add all of the flour and mix well to make a smooth, thick blondie batter.
Crush the meringues into medium-sized pieces then fold them into the batter along with the lemon zest and white chocolate chips.
Transfer the blondie batter to your lined tin and spread it out evenly.
Bake for 35-40 minutes, until the edges are pulling away and look golden brown. The middle should be shiny and lightly golden but still have a slight wobble.
Leave the blondies in the tin to cool completely then put them in the fridge for 3-4 hours to set. This will make the gooey centre turn firm and fudgy.
Once set, sprinkle with extra meringue pieces, cut into squares and enjoy!