Lemon bars with gluten free shortbread crust
These lemon bars are a must if you love lemon curd as much as I do. The lemon curd filling is extra thick and creamy on a buttery and delicious gluten-free shortbread crust. The addition of avocado oil gives the lemon curd a natural yellow colour. They are simply the best lemon bars and are perfect for sharing at parties, picnics and bake sales.
Today I am so excited to share with you these little bites of heaven. This is the best and only lemon bars recipe you will ever need and what is even better is that the base is deliciously gluten-free. The process is very simple and I have included some step to step pictures to help you along the process. Grab yourself some lemons and let’s bake!
Tips for the lemon curd bars
Use gluten-free self raising flour: There’s a big difference between gluten free plain/self-raising flour’ and a *singular* type gluten free flour. When I say ‘gluten free plain or self-raising flour’ in a recipe, I mean a BLEND of gluten free flours, not just one, singular flour. Most gluten free flour you buy in the supermarket typically contains a blend of rice flour, potato flour, maize flour, tapioca flour AND buckwheat flour. That’s a lot of different flours! If your flour doesn’t contain xantham gum simply add 1/4 tsp of xantham gum.
Use fresh lemon juice: I know it is convenient to use the bottled stuff but trust me that the flavour is nowhere near the same. You will need 3-5 lemons depending on the size.
Cook the curd over low heat: The curd really needs to be cooked over low heat as any higher would curdle the eggs and you would end up with a frittata!
Refrigerate your lemon bars: After your bars are cooked and cooled they need to be refrigerated, to ensure they set completely before cutting.
Ingredients for the lemon bars
Caster sugar: For an extra buttery shortbread I do prefer to use caster sugar as its fine crystals incorporate easier with the butter.
Gluten free self raising flour: As I mentioned earlier you can’t just swap gluten free self raising with any other kind of gluten free flour. If you are not too bothered about your bars being gluten free you can simply use regular self raising flour.
Fresh lemon juice: As tempting as it is to buy the bottled stuff please don’t! They are convenient but you really do miss out so much on the flavour of fresh lemons.
Fresh egg yolks: Ok I know 6 egg yolks sounds like a lot but it is the reason why this curd is so creamy. Why not use the egg whites to whip up a batch of tiramisu macarons?
Lemon zest: If the lemon juice wasn’t enough citrus for you I also added some lemon zest for an extra kick!
Cornstarch: I added a little bit of cornstarch to ensure that the bars set beautifully and are easier to cut.
Avocado oil: Ok I know this a weird one but hear me out! I added a small amount of avocado oil and the green colour of the oil gave the lemon bars a natural yellow colour as I didn’t want to add any artificial colouring. You can of course replace the avocado oil with some extra virgin olive oil.
For the gluten-free shortbread base
- 150g unsalted softened butter
- 75g caster sugar
- 210g gluten-free self-raising flour
For the lemon curd filling
- 170ml lemon juice (about 3-5 lemons depending on the size)
- 300g caster sugar
- 1 tbsp lemon zest
- 5 egg yolks
- 1 1/2 tsp cornstarch
- 60g unsalted butter
- 60ml avocado oil( or extra virgin olive oil)
- Pinch of salt
How to make the lemon bars
- Preheat your oven to 160C fan. Prepare a 9×9 inch square pan with non-stick baking paper.
- Beat together your softened butter and sugar until smooth. This shouldn’t take very long – an electric hand mixer would be ideal.
- Add in your flour and mix again. Mix until there is no white flour showing but it still looks like its all more crumbly bits.
- Bring the dough together in your hands, ensuring you don’t overmix it.
- Firmly press the mixture into the bottom of the tin and bake in the oven for 20-25 minutes until pale golden on top!
- While the shortbread is baking, prepare the lemon curd: Grate 1 tablespoon of zest from the lemons and set aside. Squeeze lemons to yield 200ml of juice.
- In a small saucepan, mix lemon juice half the sugar and bring to a light simmer over low heat. In a separate bowl add the rest of the sugar together with the cornstarch and whisk until thoroughly combined. Add the egg yolks to the cornstarch and sugar mixture and whisk for around 30 seconds until the mix has turned slightly pale.
- Pour half the simmering lemon juice into the mixing bowl (*see Notes) and whisk again till there are no lumps.
- Return the mixture back to the remaining lemon juice in the pan.
- Continuously whisk the mixture until it comes to a boil. Make sure the mixture comes to a boil and stays there for 30 seconds or so; you should see it thicken up before you take it off the heat. But once it boils do not cook for longer than 1 minute or you risk the curd thinning out again. Remove from heat, whisk in butter, avocado oil(or olive oil) and lemon zest.
- When the shortbread is ready, take it out of the oven and carefully pour the lemon curd onto the warm shortbread base; return the tin to the oven. Bake until topping is just set, 10 to 15 minutes more. Allow to cool to room temperature, then refrigerate until cold before cutting into bars. Dust with icing sugar right before serving.
- Pouring some of the hot lemon juice in the whipped egg yolks and sugar is called tempering and it prevents the egg yolks from curdling. We don’t want scrambled egg lemon bars.
- Freezing Instructions: Lemon bars can be frozen for up to 2-3 months. Cut the cooled bars into squares, then place onto a baking sheet. Freeze for 1 hour. Individually wrap each bar in cling film and place into a large bag or freezer container to freeze. Thaw in the refrigerator, then dust with icing sugar before serving.