Bake Play Smile
Place the butter into a microwave-safe bowl. Heat in the microwave for 2-3 minutes in 30 second bursts until the butter has melted. Add the brown sugar and caster sugar and stir to combine.
Add the eggs (including the extra egg yolk) and the vanilla extract and whisk until combined.
Sift the plain flour, cornflour, baking powder and salt into the bowl and gently fold through. Stir through the white chocolate chips.
Sprinkle over the crushed Biscoff cookies.Pour into the prepared baking tin.Place small dollops of Biscoff spread over the top of the blondie batter. Bake for 25-30 minutes or until cooked through.