Lemon Curd Crumble Bars
Flakey, tender lemon shortbread filled with tart and creamy lemon curd and topped with more shortbread crumble. These bars are incredibly quick and easy to make and are a perfect spring or summer treat!
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Why this recipe works
First, the shortbread. This is one of my most beloved recipes, used as a cookie on its own or the base for several thumbprint cookies. While not everyone loves shortbread, my friends and family seem to all love mine!
My secret is powdered sugar. It is a very fine texture, meaning you’ll get a smooth, fluffy dough without any large sugar crystals. And while some recipes call for beating granulated sugar until nearly dissolved, I’ve found that to be 1. often impossible and 2. too much air in the dough for the delicate, crumbly cookie we want.
Additionally, confectioner’s sugar has a small bit of cornstarch. Cornstarch is that secret rising agent that gives just a slight poof. It keeps these cookies from being dense yet isn’t powerful enough (like baking powder/soda) to make them rise like a chocolate chip cookie. It creates that perfect in-between rise.
As well, European style butter is a game changer. It has far less water and is a MUCH creamier butter, making softer, more tender cookies. I get Kerrygold from Costco (in fact, it keeps going on sale and now we have at least 18 pounds in our fridge for all my summer baking…). But any European style butter will do. I often use salted butter, meaning I only add a pinch of salt. This is because I know Kerrygold and know how salty it will make my dessert. If you’re using a different brand or are unsure, try to use unsalted so you can better control the salt.
Second, the lemon curd. This lemon curd was a happy accident. I wanted to try my hand at it, but I didn’t want it too eggy or too runny. So, I played around with the recipe a bit and found this curd that is incredibly creamy yet still tart and all-around delicious.
Key ingredients
Butter. As mentioned above, always use European style butter in shortbread. It’s creamier and has less water.
Confectioner’s sugar. This is the secret to the tender texture and perfect sweetness of these cookies.
Vanilla extract. Use pure vanilla extract, not imitation.
Salt. Only use a pinch or so if using salted butter.
Flour. Optionally, you can sift this before using, making the cookies even more tender and delicate.
Lemon zest. Surprisingly, just a tablespoon of zest is enough to give these a great flavor!
Lemon curd. I recommend making homemade, as it’s pretty easy. However, store bought would work, too.
How to make lemon curd crumble bars
1. Cream butter and powdered sugar. You don’t need to beat it for a long time, just make sure it’s well-combined and perfectly smooth.
2. Add vanilla and salt. Reduce salt to a pinch if you used salted butter. Be sure it’s very smooth so that the flour can be mixed in minimally.
3. Stir in flour. Technically, you could sift and whisk the salt and flour, but that requires an extra bowl, and I just don’t have the patience for more dishes. So, I add the salt to the butter most of the time.
4. Press 2/3 of the dough into a lined pan.
5. Par-bake. This helps the bottom layer bake without burning the curd or the crumbles.
6. Spread lemon curd. You can cool the crust if desired or just spread the curd right onto the warm crust.
7. Crumble remaining dough. Don’t worry if some curd is visible.
8. Bake until matte and slightly golden. You can’t really use a toothpick to see if it’s done, so you’re really just looking for the crumble to appear done. It should no longer be shiny and should just start to brown along the edges.
Enjoy!
Tips and FAQ’s for this recipe
Is store-bought curd okay?
Yes! I LOVE my homemade curd, but honestly, sometimes you just need a quick dessert. I really love both Trader Joe’s and Bonne Mama’s lemon curd. Both would be great in this recipe.
What do I serve this with?
Anything! This is perfect on a picnic or with coffee or tea! Or just to keep on the counter for a quick little something sweet. You can also top it with ice cream, like my razzleberry swirl ice cream. The possibilities are endless!
Do I have to use European butter?
Personally, I think it makes a huge difference. It’s creamier and has a very different consistency than sweet cream butter. Since you only have a few ingredients here, you want to make sure each one is of the highest quality. But don’t worry—you can often find it at places like Costco on sale!
What if I don’t have powdered sugar?
You can technically make your own, but I can’t vouch for its efficacy in cookies (it works well in buttercream). Simply place 1 cup granulated sugar and 1 tablespoon cornstarch in a blender and mix until fine—the texture of powdered/confectioner’s/icing sugar. You can of course increase the amount, but this will give you more than you need already.
Do NOT over mix!
These will become tough and lose their flaky tenderness if you mix them too much. Be careful to stir just until the dough comes together then stop. If you find any unmixed flour, you can pat that into the rest of the dough when you roll it out.
Can I make these ahead of time?
Yes! You can make the dough and refrigerate it (well sealed) for up to three days. If you need to make them further ahead, you can freeze the dough. Just let it thaw in the fridge then come to room temperature for a few minutes on the counter. Fully cooked bars can be made 1-2 days ahead, but tightly sealing them actually causes them to become overly moist and lose their flakey crunch, so just cover the pan with foil OR cut and freeze, wrapping individually. They will last 1-2 months in the freezer.
My tools
Here are my must-have tools I use for making these bars. Affiliate links provided.
Mesh sieve (because sifting is KEY for a perfect shortbread)
Lemon Curd Crumble Bars
- prep time: 25-30 minutes (if making lemon curd)
- bake time: 25-30 minutes
- total time: 1 hour
servings: 9-16
Ingredients:
- 2 cups (240g) flour, spooned and leveled then sifted
- ¼ teaspoon (2g) finely ground sea salt (omit if using salted butter)
- 1 cup (227g) unsalted European style butter, softened
- ⅔ cups (87g) powdered sugar
- 1 tablespoon (13g) vanilla extract
- zest of 1-2 large lemons
- half a batch of tart and creamy lemon curd (or one jar store bought)
Instructions:
- Make the lemon curd ahead of time, letting it cool in the fridge at least one hour.
- Preheat oven to 350F/175C. Line an 8x8 pan with parchment paper. (One easy way to do this is to turn the pan upside down and fold the parchment around it, then flip the pan over and place it in with the folds.)
- Finely zest your lemons using a microplane zester.
- In a small bowl, whisk together flour and salt. Set aside. (Optionally, you can just add the flour and salt to the butter once it’s blended).
- In a medium bowl (or the bowl of a stand mixer--I couldn't use mine because it does best with larger quantities), whip the butter with a handheld electric mixer on high until creamed, about 30 seconds. Add powdered sugar and mix on high until light and fluffy, about 1 minute. Add vanilla then mix, starting on low then increasing to high to fully incorporate.
- Scrape the bowl then sift in the flour. Add the lemon zest and mix on low until fully incorporated. It will be crumbly at first then will suddenly start to stick to the beaters and pull away from the sides of the bowl. At this point, stop mixing.
- Press about ⅔ of the dough into the bottom of the pan, being sure to seal the edges so the curd doesn’t seep underneath.
- Bake 15-20 minutes, until it is matte in appearance and just barely begins to turn golden. You can then let it cool before the next step, but that’s not necessary.
- Spread about 1 cup of curd on the crust. Crumble the remaining dough on top. Don’t worry if there are some gaps with curd showing through.
- Bake about 10-12 minutes more, until the crumbles are matte and the edges begin to turn golden. Let cool completely in the pan.
Enjoy! Bars will last loosely covered for 3-5 days. An airtight container will actually cause them to soften after a day, so cover loosely.