Preheat the oven to 350°F.
Spray a 9 x 13” pan with cake release and double-line with parchment paper, ensuring the paper is 1” higher than the pan. These steps will make it easier to get the lemon bar out of the pan after baking.
Place all the crust ingredients into a mixing bowl. Use the paddle attachment on slow until the mixture resembles breadcrumbs and starts to form into a ball.
Tip the mixture into the pan and use your fingers to press the mixture down evenly.
Cut a 9 x 13” rectangle of baking paper and place on top. Apply firm pressure with a cake smoother polisher to flatten the base and make it smooth.
Remove the paper and prick the crust with a fork. Bake for 18-20 minutes until golden.
While the crust is in the oven, clean out the mixing bowl and whisk together the flour and sugar to make the topping.
Add the eggs, egg yolks and lemon juice and mix until combined either with a whisk or a hand blender. If using a hand blender, keep the blade under the mixture to avoid incorporating air.
Remove the baked crust from the oven and reduce the temperature to 320°F.
Strain the mixture into a jar and pour over the crust.
Bake for 20-25 minutes until set. It is ready when you shake the pan, and the topping doesn’t wobble.
Remove from the oven and allow to cool (about an hour) on a cooling rack before transferring it to the refrigerator. Refrigerate for at least 3 hours.
When you are ready to serve, gently pull the sides of the baking paper to carefully lift it from the pan.
Transfer to a cutting board and trim off the edges with a sharp, hot knife. Wipe it clean after every cut.
Cut into 24 bars and dust the tops with powdered sugar.