The best lemon meringue bars: these have a crumbly poppy studded shortbread crust, a buttery puckery lemon curd filling and a very vanilla marshmallow meringue on top.
Before you get to the recipe, I need to warn you: you will require *ten* eggs for this. I can’t emphasize to you enough how hard I took that. The broke college girl inside of me is still cringing. You’ll need to buy an extra carton of eggs just for this recipe and a whole bag of lemons… BUT, I promise if you follow the steps closely you’ll have the most perfect lemon bars ever and it will be worth it!
Why are these the best lemon bars, sam?
Let’s start from the bottom up: I’m sorry but have you ever met a buttery, crumbly shortbread crust you didn’t love? On cheesecake bars? Blueberry bars? Even brownies have gotten a softly sweet shortbread bottom. I was not about to boring-graham-cracker this meticulously crafted recipe.
The curd: this is LEMONY and sharp. Which is why it’s the best, to me at least. I’m not shy about my love of a really puckery lemon taste. This isn’t the first time you’ve seen this lemon curd, it was on a cheesecake here, in a baklava pie here, in a ganache here and most recently stuffed into these cookies. It’s so LUSH and smooth. I used to think I’d never make a better lemon curd than Ina’s one but then I made the filling from this pie and have been tweaking it over the past year. Doing away with just using yolks helped mute the egginess, and allow the lemon to shine, and I’ve changed the method a lot – you’ll see it below. Now, I’ve finally nailed down *my* perfect curd. It’s buttery, smooth and very sharp.
The meringue: you know this girl loves her a fluffy, silky meringue and will find literally any excuse to make one. I have a few methods that ensure my meringues turn out and for this one I doubled down on the vanilla. Often, just a bean or just the extract doesn’t give me as much sweet vanilla flavor as I like so here we’ll use both.
Eggs: Large eggs. Straight from the fridge is fine. For the meringue, if you can remember – separate the eggs when cold and then leave them at room temperature until you begin making it.
Lemons: Size matters a lot here, mine were medium sized I’d say but if yours were small you’ll probably need 10-12. And if they are large, 5 might be enough. The stage at which the lemon is will yield fresher juice. If they are hard and a bit green the zest won’t be as sweet and they’ll be harder to juice. If they have gone a bit soft and brownish they are still good to use – but smell them to be sure.
Butter: For both the shortbread and the curd. Fat percentage doesn’t matter a huge amount here so use whatever you have on hand. It can be cold or at room temperature for both the crust and the curd. In both cases mixing will just take longer if it’s cold.
Flour: For the crust, any all purpose flour is good. If you want this to be gluten-free use a 1 to 1 substitute flour and that should work well.
Salt: Don’t skip this and use fine sea salt. Table salt is much saltier so it’s a poor substitute here. Salt enhances the flavor of the curd and dims the sweetness of the meringue. I add it with the eggs because it helps break down the white when it’s whisked.
Vanilla: Use a good quality vanilla for the meringue because it’s the dominate taste. If you don’t have or don’t want to purchase vanilla beans, use more extract, about 2 tsps in the meringue.
Sugar: cannot be reduced or substituted for in the meringue as it is what stabilizes the whipped egg whites. Use a fine granulated sugar as it will dissolve more quickly in the curd and meringue.
Let’s start with the curd, because it can be made ahead of time and stored in an airtight container (I use a mason jar) and poured over the crust when it’s time to make the bars.
To get started, set a bowl with the butter (sliced) and a sieve over it.
Then straight into the pot begin by rubbing the sugar and zest together, this helps release the oils so you get more of that sweet lemon flavor. In a separate bowl, whisk the eggs with the salt, really really well to help break up the white bits.
Then add the lemon juice to the pot and stir. Pour in the eggs and whisk, whisk whisk. Set it over medium low heat.
Now switch to a rubber spatula. Stir the curd as it heats, cooks and thickens. Once it covers the back of the spatula, it’s done cooking. Stay close-by, watching it so you don’t overcook it.
Now pour it through the mesh sieve, this is to strain out the zest but also any white bits of egg left in there. Scrape the bottom of the sieve so you can catch all the curd possible. Then use a clean spoon to stir until the butter is fully melted and incorporated. At this stage you can transfer it to a jar and refrigerate if you aren’t ready to make the bars.
Once the crust is baked, pour the curd in (crust info below) and then use a toothpick to pop some of the bubbles. Return it to the oven and bake until mostly set (the middle might be slightly jiggly), it will thicken and set more as it cools. Refrigerate this for at least a few hours, or even overnight before you make the meringue.
Meringue time! Meringues don’t last long once they go on wet fillings so only start this step on the day of serving.
First bring a pot filled 1/3 of the way with water to a soft simmer. Get a heatproof bowl that can fit over the pan without touching the water (but don’t put it in the heat yet) and pour in the sugar, then the eggs and quickly whisk them. Put the bowl over the pot and whisk, whisk whisk.
Check it by pinching the mix with your fingers; can you detect sugar granules? If so keep warming it. Once you can’t, it’s ready to be taken off the heat.
Pour it into the bowl of a stand mixer fitted with the whisk attachment. Turn the mixer to medium speed and let it whip; it can take up to 10 minutes to get to stiff peaks; ie when you can turn the whisk upside down and the mixture doesn’t droop. While it’s whisking you’ll add your vanillas & salt.
The goal with the crust is just to get all the ingredients mixed together. If the butter is cold or you are doing this by hand it will take a bit longer. Once it’s all incorporated add the poppies (they are optional but really delightful) and then press it into the bottom of a square pan in an even layer. Then bake.
Once the meringue is ready spread it over the cold lemon curd in an even layer (but don’t be shy of making some nice swoops with the back of a spoon). Put the pan back in the fridge so meringue can set.
When it’s time to serve, ready your broiler on high. Put the pan under the broiler and watch it, it won’t take more than 2-3 minutes to brown.
Use a clean, heated but dry knife to slice into the bars. (You can heat the knife by placing it under hot water, but dry it before slicing).
The curd didn’t thicken in the pan, or didn’t set once baked
The curd thickens when brought to 170 F. You may need to cook it longer. Some bakers make theirs in a double boiler so that they don’t have to worry about burning it, and if you are doing this note that it will take longer.
Also remember to stir it often while it’s cooking. Since the heat is at the bottom it will thicken there first, you want it to cook evenly so to distribute the heat all over you need to keep stirring.
There were white bits in the curd
White bits are from the egg, they were cooked before they got mixed with the rest of the ingredients. Avoid this by whisking the eggs really well. I almost always have a few of these, they will be sieved out once the curd is cooked.
The meringue didn’t reach stiff peaks
By hand or by mixer it’s almost impossible and very difficult to get a perfectly whipped meringue. So first, make sure you’re using the right tools.
If this happens it could be that something got into the mix that’s stopping the proteins from holding; a little bit of egg yolk, some oil, or even a dirty bowl. It could be that the meringue was whisked past stiff peaks, after it reaches it begins to break down. I’ve heard that you can add an egg white to bring it back to stiff peaks but it’s never worked for me. You’ll likely have to start over.
Lastly, if your kitchen is very humid you’ll have a tough time getting those peaks.
The meringue has bumps in it
This is undissolved sugar and means that the egg/sugar mixture wasn’t heated long enough.
You sure can, just make a traditional pie crust and once it’s fully baked pour in the curd, bake it and then chill it. Then top with the meringue.
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