Creamy, crumbly, and refreshing, these oatmeal lemon crumble bars come together with a simple crumb crust and a 2-ingredient lemon filling. If you love lemon bars but are looking for a little more texture, you won’t regret making a batch!
I originally published these lemon crumble bars back in 2012. When making these a decade ago, I used store-bought cookie mix for the crust and topping. While cookie mix makes a quick and handy shortcut, I prefer these bars with a from-scratch crumble… and I think you will too!
Today I’m showing you my homemade variation and I promise they’re nearly just as easy. The oatmeal lemon crumble bars have a way of not making it out of the kitchen, but should any survive your taste-testing, they stack and store easily for gift-giving, bake sales, and brunches!
Why You’ll Love These Oatmeal Lemon Crumble Bars
- Only 9 simple ingredients total
- Crust and topping are made from the same mixture
- From mixing bowls to oven in 15 minutes
- Altogether creamy, crumbly, soft, & crisp
- Like oatmeal chocolate chip cookies (minus the chocolate!) & lemon bars combined—surprisingly, this flavor duo works!
- Stack easily for storing, transporting, & gifting
- Another egg-free baking recipe
And feel free to swap in lime juice & zest for the lemon!
You Need 9 Ingredients Total:
- 7 for the crust & crumble topping: Like fig bars, cherry pie bars, peach bars, and cranberry bars, the crust and topping are made from the same mixture. So convenient! Start with butter and brown sugar, and then add vanilla extract before mixing in flour, baking powder, salt, and oats.
- 2 for the creamy lemon filling: You need sweetened condensed milk and lemons to make the lemon filling—that’s it! Have you ever tried my creamy lemon pie? I actually adapted that recipe from today’s filling. Sweetened condensed milk is the base of this filling and as it bakes, it thickens and takes on a slightly caramelized flavor. (Like when making dulce de leche for banoffee pie!) Unlike the lemon pie, we don’t need any eggs in the filling because we aren’t looking for quite as much structure; the crumble topping holds everything in place!
Let Me Show You How These Come Together
Pictured below on the left: Bring the crumble mixture together and do not get nervous if it seems dry or crumbly.
Pictured below on the right: Press half of the mixture into a lined 8-inch pan and bake it for 12 minutes so the crust can set.
PS: Here’s how I like to line square baking pans. So easy! Lining the pan makes it much easier to remove the bars before slicing and serving. I use the same tip when making rice krispie treats and M&M cookie bars, too.
Expect a very thick lemon filling. I actually add a little more lemon juice than the original recipe and the printable recipe below reflects that change. Pour and spread the filling on the warm crust and then sprinkle with remaining crumble mixture. That’s it! Your prep work is done.
3 Success Tips
Though it’s a really easy recipe, here are 3 success tips that have helped me perfect these creamy lemon bars.
- Don’t pack the crust in too tight: When pressing the mixture into your lined pan, avoid packing it in too tight. If the crust is very firm even before baking, imagine how dense it will be after baking. Press the mixture down very lightly with your hands or the bottom of a measuring cup.
- Use a citrus zester: Lemon zest carries a lot of flavor in the lemon filling. If you need a recommendation for a zester, I use and love (affiliate link) this zester.
- Avoid over-baking: It can be difficult to determine when the bars are done, but err on the side of under-baking. And keep in mind that the bars will continue to set as they cool. If over-baked, the crust and edges will be quite firm. Once the fully assembled bars go in the oven, they take about 23–25 minutes.
And lastly, you need an (affiliate link) 8-inch pan for these creamy lemon bars. Stretching the recipe into a 9-inch pan yields very thin bars, so I don’t recommend that size.
PrintOatmeal Lemon Crumble Bars
- Prep Time: 15 minutes
- Cook Time: 38 minutes
- Total Time: 2 hours (includes cooling)
- Yield: 16 bars
- Category: Bars
- Method: Baking
- Cuisine: American
Description
These easy lemon crumble bars feature an oatmeal crust, thick and creamy lemon filling, and more oatmeal crumble on top.
Ingredients
Crust & Topping
- 7 Tablespoons (99g) unsalted butter, softened to room temperature (yes, 7 Tbsp!)
- 3/4 cup (150g) packed light or dark brown sugar
- 1 teaspoon pure vanilla extract
- 1 cup (125g) all-purpose flour (spooned & leveled)
- 1 teaspoon baking powder
- 1/4 teaspoon salt
- 1 cup (85g) old-fashioned whole oats or quick oats (not instant)
Lemon Filling
- 1 (14-ounce weight) can full-fat sweetened condensed milk
- 6 Tablespoons (90ml) lemon juice (about 2 lemons)
- 1 Tablespoon lemon zest (about 1 lemon)
Instructions
- Preheat oven to 350°F (177°C). Line an 8-inch square pan with parchment paper.
- For the crust/topping: Using a handheld or stand mixer fitted with a paddle attachment, beat the butter and brown sugar together on medium-high speed until combined, about 1 minute. Scrape down the sides and up the bottom of the bowl with a rubber spatula and then add the vanilla extract. Beat on medium-high speed until combined, about 30 seconds. Add the flour, baking powder, salt, and oats. Beat on medium speed until combined. Scrape down the sides and up the bottom of the bowl and beat again as needed to combine. Mixture will appear dry and be crumbly. You will have between 3–3.5 cups of crust/crumble mixture.
- Lightly press a little more than half of crumble mixture into bottom of prepared baking pan. (You want a little more mixture for the crust than for the topping.) Bake for 12 minutes.
- Meanwhile, make the lemon filling: Whisk sweetened condensed milk, lemon juice, and lemon zest together. Mixture will be thick.
- Pour and spread filling over pre-baked crust (while crust is hot). Sprinkle the remaining crumble mixture on top.
- Return bars to the oven and bake for 22–25 minutes or until edges are very lightly browned and appear set. Avoid over-baking. Remove from the oven and place the pan on a wire rack. Cool bars completely.
- Lift the bars out using the parchment paper overhang on the sides. Cut into squares.
- Cover leftover bars and store at room temperature for up to 2 days or in the refrigerator for up to 1 week.
Notes
- Freezing Instructions: Freeze cut bars in single layers between sheets of parchment paper in a freezer-friendly container for up to 3 months. Thaw overnight in the refrigerator and bring to room temperature before enjoying.
- Special Tools (affiliate links): 8-inch Square Baking Pan | Parchment Paper | Electric Mixer (Handheld or Stand) | Glass Mixing Bowl | Whisk | Zester | Juicer
- Recipe updated in 2022: Older version used 1 pouch (1 lb 1.5 oz) Betty Crocker oatmeal cookie mix for the crust & topping. Cut 1/2 cup (115g) cold unsalted butter into cookie mix with a pastry cutter and then stir in 1 egg. This mixture replaced the homemade crust & topping recipe above. Continue with step 3 above.
- Sweetened Condensed Milk: Make sure you are using sweetened condensed milk, not evaporated milk. There are no successful replacements for sweetened condensed milk in this particular recipe—it’s really the key ingredient. (Sometimes half-and-half or heavy cream works as a substitution, but then you’ll have to test with varying amounts of sugar since both are unsweetened.) Use one 14-ounce can full-fat sweetened condensed milk. Do not use fat-free because the filling will not set. Keep in mind that 14 ounces is the listed weight on the can. 1 standard 14-ounce can is a little over 1 liquid cup.
- Can I Double This Recipe? Yes. Double each ingredient and bake in a 9×13-inch pan. Increase crust pre-bake time to 18 minutes. Increase the bake time after adding the filling & crumble topping to 35 minutes, or until edges are lightly browned and appear set.
Any good way to make this gluten free? Sub flour with almond flour or oat?
Hi Andrea! We don’t recommend almond flour as it has very different baking properties and is not always a 1:1 swap. We haven’t tested it, but you might have success experimenting with a gluten-free all-purpose flour like Bob’s Red Mill or Cup4Cup. If you give anything a try, we’d love to know how it goes!
I used Bobs Gluten Free 1:1 and they came out great!
Greetings Sally, this looks delish! thinking of making for Easter and will have a gluten free guest attending… do you think we could substitute almond flour for regular flour? thank you!
Hi Jessica! We don’t recommend almond flour as it has very different baking properties and is not always a 1:1 swap. We haven’t tested it, but you might have success experimenting with a gluten-free all-purpose flour like Bob’s Red Mill or Cup4Cup. If you give anything a try, we’d love to know how it goes for you!
Could I use lemon curd in this?
Hi Mary, we don’t recommend replacing the lemon filling with lemon curd. Lemon curd won’t quite set up the same here. You could drizzle some lemon curd on top of the finished bars if desired.
Wonder if I could replace the lemon filling with prepared lemon curd?
Hi Bekah, we don’t recommend it. Lemon curd won’t quite set up the same here. You could drizzle some lemon curd on top of the finished bars if desired.
Do you think sweetened condensed coconut milk would work? We have a dairy allergy in the house. And thinking that with either lemon or lime would be delish.
Hi Kelly, we haven’t tried, but it should work! Let us know how it turns out if you do.
7 tbsp butter.
Really
,how do you measure out 7 tbsp
Everyone does not have butter in sticks
Hi Audrey! The weight (100g) is listed as well.
Hi, can I substitute coconut oil for the butter?
Hi Hafiza! Solid coconut oil should work here, but we haven’t tested it. The flavor will change, and the texture may be a little greasy. Let us know if you give it a try!
How do you accurately measure butter with a tablespoon,
Hi Audrey! Usually butter sticks come marked with Tablespoon measurements. You can always use the weight measurement (100g) for the most accurate measurement.
I really like these, however my crumble topping was too loose. Will add a bit more butter next time. Thank you.
This recipe was a fail for me. It never setup. I let it dry out for a few days. Then I managed to cut it into small squares. Everyone loved it.
This went down amazingly well the only thing I did was add an extra tablespoon of lemon and it was delicious everyone said it was the perfect amount of lemon not to add anymore or any less
Thank you for a fabulous recipe
Hi there any idea of nutritional value per piece ( based on 16 portions ) I am baking for a school and they need this info…..
otherwise – amazing, love love it.
Hi Helen! We don’t usually include nutrition information as it can vary between different brands of the same ingredients. Plus, many recipes have ingredient substitutions or optional ingredients listed. However, there are many handy online calculators where you can plug in and customize your exact ingredients/brands. Readers have found this one especially helpful: https://www.verywellfit.com/recipe-nutrition-analyzer-4157076
AMAZING Lemon Bars!!!
Delicious and easy, but needs more citrus. I’d double the amount of lemon juice next time. Not tart enough
Just SO good!! Easy to make and so delicious. I love that the crumble works both as the crust and as the topping, so fewer steps. The filling is creamy and very lemony, but not too tart. I baked for 21 minutes, and that seemed perfect. Will definitely make again!!
Ummmm Omg these are to die for. Another winner from Sally! YUMMM. Def need to double the recipe next time because these won’t last long.
Can leave out the oats or replace them?
Hi Irina, oats are key for giving these bars their shape and structure. For an alternative without oats, you may like these lemon bars instead.
Is the oven temp fan force ? Looking forward to making these 🙂
Hi Cate, All of the recipes on this site are written for conventional settings. Convection ovens are fantastic for cooking and roasting. If you have the choice, we recommend conventional settings when baking cakes, breads, etc. The flow of air from convection heat can cause baked goods to rise and bake unevenly and it also pulls moisture out of the oven. If you do use convection settings for baking, lower your temperature by 25 degrees F and keep in mind that things may still take less time to bake.
These lemons bars are so incredibly, OMG!!!!! Almost ate all of them.
Lemon LOVE this recipe!!! We have an over abundance of lemons right now, so I’m looking for easy ways to use them up. Last night we had lemon chicken, lemon roasted broccoli with roasted sweet potatoes, and these beauties for dessert! YUM!
Thank you, Sally
Sounds like an incredible meal, Pamela!
These bars are really good and such a nice change form all my usual recipes. I decided to use foil to line my pan, for nicer corners, but it was a big mistake. It’s stuck to the bars and I lost about a quarter inch on each side, trying to get the foil off. Next time will use parchment.
My third time to make this recipe..Super easy to make and lemony goodness! A winning recipe, indeed!
LOVE LOVE LOVE this Recipe!
Another outstanding recipe from Sally & Team …
Thank you!!!!
Just two words “Oh My” These are so good. Even better the next day.
Made these as written and they were perfect and delicious!
I’ve been making these a few times a month for a year (my boyfriend runs a fly fishing camp) and the guests LOVE them. Every single time. I do them with lime…I’m in Belize and it’s all limes, few lemons…and they get raves.
Made these twice now and they were delicious and a big hit each time. Thanks!
I made the recipe exact and it was an utter fail. There is too much crumb topping on top and it is quite loose and messy as a result. The lemon center merged in with the top and bottom, nearly disappearing. The end product had a reasonable taste but bore no resemblance to a lemon bar. The crumb top and bottom were just too much and detracted wholly from the lemon center. I ended up throwing it all away. I’d stick to a more traditional recipe in the future.
I made these today for the first time. Oh my goodness — they were so delicious. I found the instructions so easy to follow and the recipe to be a quick, easy one. I can’t wait to try all the other crumb bar recipes soon. These were such a hit with everyone at the cookout we attended. Thank you for always sharing great recipes!
Fantastic!! I made these today and just had one. OMG! I followed the recipe to a tee and I highly recommend all trying it out. Love the texture it gives as Sally states from the traditional lemon bar not having it The crumble crust and topping is so yummy I can’t wait to make other things using it. Thank you for such wonderful recipes and excellent instructions