These are the perfect lemon bars with a buttery shortbread base and a sweet and tangy lemon layer. The bright lemon flavor tastes like sunshine - making these perfect for spring and summer. They only require 7 simple ingredients and set beautifully.
Preheat the oven to 325F (160C) degrees. Line a 9x13 inch pan with parchment paper, leaving an overhang around the edges.
Shortbread Base
In a large bowl whisk together the flour, sugar, corn starch and salt.
Stir in the melted butter. The dough will be thick.
Press the dough into the bottom of the lined pan and create a small lip around the edges.
Bake in the preheated oven for 20 -25 minutes, or until the base looks set and is just started to look golden around the sides. Make the lemon layer as the base is baking. Remove from the oven (and keep the oven turned on).
Lemon Layer
Whisk together the sugar and cornstarch to remove any lumps.
Whisk in the eggs, followed by the freshly squeezed lemon juice.
When the base is done baking, remove it from the oven. Gently prick the very top of the shortbread with a fork (just go deep enough to prick the surface).
Pour the lemon filling over top of the base and bake in the preheated oven (still at 325F) for 20-25 minutes, or until the top looks set and no longer wobbles like a liquid if you gently nudge the pan.
Remove from the oven. Cool the bars in the pan at room temperature for about 1 hour, then pop the pan in the fridge to chill for at least 2 hours.
When ready to slice, remove the bars from the fridge. Lift them out of the pan by using parchment paper overhang from the horizontal sides of the pan.
Place on a cutting board and slice using a sharp knife. Optionally, sprinkle with powdered sugar.
Notes
This recipe can be halved and made in an 8x8 inch pan. The bake time will be about 20 minutes for the base, and about 20 minutes for the lemon layer.
Store bars in an airtight container in the fridge for up to 5 days. Bars can be wrapped tightly and frozen for up to 2 months in a freezer container. Thaw in the fridge.
Make sure to use freshly squeezed lemon juice - do not use lemon juice from the bottle because it is too sour. You'll need about 5-6 small lemons or 4-5 large lemons for 1 cup of lemon juice.
Nutrition information is an estimate only and based on 1 bar, assuming the pan is sliced into 18 equal pieces.