Step 1

Preheat your oven to 325oF (170oC) then butter and line an 8x8 inch baking tin, set aside.

Step 2

In a large bowl combine the sugars and the flour. Next rub in the butter until you've reached the texture of coarse breadcrumbs. Continue to bring the shortbread together using your hands until the dough forms a ball.

Step 3

Transfer the shortbread dough to your lined baking tin and press into one even layer using your fingertips and the palm of your hands. Then prick the crust all over with a fork.

Step 4

Bake the shortbread crust for 25 minutes. While the base is baking, make the lemon filling.

Step 5

In a medium bowl combine the egg yolks, sugar, soft butter, vanilla extract, lemon juice, and zest then mix to combine. If the mixture looks a bit separated, don't be alarmed.

Step 6

UPDATED STEP: lastly, whisk in the flour and  baking powder until there are no lumps. (We added this step 2018 to rectify lemon bars that were not setting)

Step 7

Remove the crust from the oven then fill with the lemon filling.

Step 8

Bake for 40-45 minutes until the top has formed a crackle crust and is golden brown.

Step 9

Allow to fully cool before dusting with powdered sugar and cutting into squares.

Step 10

Cover and store in the fridge for up to 4 days.