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, 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.
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.
Oatmeal 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 (100g) 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 (spoon & 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.
- 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.
Keywords: oatmeal lemon crumble bars
These are so quick and turned out great!
★★★★★
Easy to make. Crust was just okay. Can’t taste the lemon in the filling at all, even though I used more juice and zest than the recipe called for.
★★
Sally: Yummy! These lemon bars are so freaking good! I tried them for one of my desserts for Easter this past weekend and they were a tremendous hit!!
Great recipe if you’re craving a very sweet treat. The oat crumble overpowered the lemon filling but still a super tasty treat!
★★★★★
Super easy and super delicious! Made the recipe as written. Four out of five coworkers said they were the best ever. The fifth person ate at least three bars so I think he was okay. I’ll start keeping sweetened condensed milk just for these bars.
★★★★★
These where great and I made them using gluten free flour !
★★★★★
Hi – what if I don’t have lemon zest. Can I add more lemon juice to compensate or will that make it too liquidy?
I wouldn’t add more juice for that reason– you can just omit the zest if needed. You will lose a little flavor.
Hmm, the cookie part was delicious. The filling part reminds me of key lime pie but lemon. I like key lime pie but didn’t like it with the oatmeal cookie part. It was a texture thing for me. I’d make it again but try the crust with maybe some lemon curd or raspberry or apricot jam between the cookie layers.
The recipe worked perfectly, just not my taste.
★★★★
Would this work using the shortbread base from your raspberry bars recipe?
Hi Giselle, we can’t see why not! Then you could halve the crumble topping for on top. Let us know if you give it a try.
What happened to the old recipe using Betty Crocker oatmeal cookie mix? That was so good, one of my favorites in the site.
See recipe notes!
I made these today. They tasted pretty yummy, very lemony. But, the crumble topping is too crumbly for me. I used parchment paper on the bottom. They did not hold together well when I cut them and a lot of the topping fell off when I cut them apart. Maybe they needed more butter in the crumble so the crust & topping would hold together better.
Hi Gwen, thank you so much for giving this recipe a try. How did you measure the flour? Make sure to spoon and level (instead of scooping) to avoid packing in too much flour into your measuring cups – or use a kitchen scale. You can read more about properly measuring baking ingredients in this post.
Hi Gwen! I made these last night and had the same problem! I measured the flour properly, so I think my issue was maybe over mixing? If I try these again, I’m going to add the oats and flour and stir by hand so they are still “chunky” (mine was like sand and not holding together well).
These are amazing. Will definitely make them again. Saving a few in the freezer to go with a Chai tea on another day. Great recipe; thank you Sally!
★★★★★
Can you double the recipe and make it successfully in a 13 X 9 inch pan? I have a feeling the 8 inch pan won’t last long enough…..:)
Hi Martha, You can double the recipe and use a 9×13 inch pan!
What increases might you make for a 10 x 14 pan? I think just double might be too thin.
Thanks Sally, love your recipes! Glad you added the dates back in!!
Do these travel well? Thinking of making these for an upcoming trip.
Hi Sheri! The bars can be stored at room temperature for up to two days. For best traveling success, we recommend cutting the bars once you arrive at your destination.
You have another hit with this one! Made them for my husbands birthday party, they were gone before the cake Love all your recipes they are my go to when I need one!
Can I use canned lemon Filling?
Grace
Hi Grace, we fear a canned lemon filling would not be thick/sturdy enough to hold the weight of the top crumble. For best results, we recommend following the recipe as is. Let us know if you give them a try!
Hi Sally, I love your recipes and am curious about this one. Could I replace the condensed milk with evaporated milk and some sugar?
Hi Christy, there are no successful replacements for sweetened condensed milk in this particular recipe—it’s really the key ingredient. See recipe notes for details!
These look incredible and perfect for Easter! If I want to double the recipe, what size pan should I use? Thanks!
Hi Natasha! To double the recipe, use a 9×13 inch pan.
Will gluten-free flour work in this recipe?
Hi Patti, we haven’t tested this recipe with gluten-free flour so we’re unsure of the results, but let us know if you do.
I made them today with gluten free flour and they where great .
Thanks, Sally- I ended up making a non-lemon flavour creme with condensed milk and mixed in 1/2 tsp vanilla extract, 1/2 tsp lemon juice to cut the sweetness, and 40ml water to make up for the loss of 1/4th cup lemon juice liquid. They turned out wonderfully, although interestingly the top oatmeal layer sank into the condensed milk layer so I ended up with only a paper-thin layer of condensed milk in the middle. As this doesn’t seem to happen with the lemon version, I wonder whether the lemon juice clots the condensed milk to make it sturdier? Next time I might try leaving the water out from the condensed milk layer to see if it holds up better when it is thicker. However, they still look beautiful and taste great, I’ll definitely make them again and I might give the original lemon version a try as well just because your creme layer looks so gorgeous in that!
★★★★★
Sally! Your recipes are all amazing, your site is my go to for anything baked. I was wondering if this could be made with you lemon filling for your shortbread lemon bars. Would it be thick enough ? Thank you!
Hi Marie Eve– I don’t recommend that curd filling for these bars. The crust and topping are simply too heavy.
We loved these! I did the shortcut recipe (Rare for me), but so easy and good! Thanks Sally!
Sally I just couldn’t wait for the recipe so I made your lemon crumb bars and my family loved it-even my brother who does not like anything lemon. Thanks for another great one!!
Made these, along with Dark Chocolate Coconut Blondies, last weekend to take to a Quiz Night. We didn’t win the quiz, but everyone loved the food! Especially my friend who is allergic to eggs – so good to be able to treat her with the Oatmeal Lemon Creme Bars. These bars are soooo easy to make, and my family loved eating any crumbs that may have *accidentally* fallen off! Thanks Sally!
Made these and they are certainly hubby approved! A good change from brownies or cookie desserts.
I made these twice last weekend: one for our neighbors who had a death in the family, one for a family who just welcomed their third baby boy. BOTH have asked for the recipe, and my neighbor declared them the best thing I’ve baked! This is a simple, flavor-packed bar dessert that even non-lemon-lovers love! Thank you, Sally!
I just made these and they look beautifulllll (in the fridge right now) unfortunately I forgot the nonstick spray (as I do in 90% of recipes hahahah)
Hopefully I didn’t totally mess up!
update: They’re DELICIOUS!!! So hard not to eat them all!
Thanks for this recipe <3
Thank you. SALLY! I made these today. Fantastic! So easy to put together and bake! I took mine out at 22 minutes, perfect! This recipe will be made over and over!
★★★★★
These taste like the lemon bars at the Restaurant Rubio’s. I went for the fish taco’s, but came back for the lemon bars. Now I can make these myself. Thank you!
This is indeed a not often heard of flavour combination, but it ends up being the perfect combination of light tasting and refreshing with comforting and homespun. The recipe was an absolute breeze to put together-one of the fastest things I’ve ever made and the effort expended versus the deliciousness of the completed bars is amazing!
Hi Sally,
Made these bars last night and all I can say is WOW ! Out of this world DEEEEEELISH ! BTW, I lined my 8×8 pan with foil and then sprayed it with PAM, came out perfect =). Thanks for such GREAT recipes !
Hey Sally, I’ve got these in the oven as a gift to my Grandfather! I was just wondering what would be the best way to remove them from the pan without them falling apart?
Thanks for the recipe!
Hey Lauren! Just let them cool completely (I put them in the refrigerator for 2 hours) and cut with a sharp knife. Enjoy!