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, blueberry 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.
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 (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.
Keywords: oatmeal lemon crumble bars
I only have a 9×13 pan…would it work to 1.5x the recipe? Or double?
Hi Ellen, double each ingredient to 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.
Wonderful bars and make a great wonderful gift for someone special. The crumble crust is FABULOUS and I plan to make use of it with other recipes. You should be able to use this as a pie crust, bake separately, make lemon filling per recipe and add whip topping on top to finish. Voila!! This recipe has a lot of potential with its delicious components. Thank you so very much, Sally
Would like to try, but need a substitute for condensed sweet milk that doesn’t contain lactose. Soy-based heavy whipped cream is commercially available. Would this product serve as a substitute? Any suggestions?
Hi Robert, soy whipped cream wouldn’t be a good alternative, but there are some options out there now for nondairy sweetened condensed milk, including one made from coconut milk and another made from oat milk. Search for “dairy-free sweetened condensed milk online” and you’ll see some options. Hope this helps!
SO GOOD!!!!!
★★★★★
After making this recipe several times, The kids and I tried something different cause gram goofed.
We have blackberry bushes, the kids picked four cups.
We doubled the recipe but I only had one can condensed milk for the lemon filling. My 9 year old GD decided we were going to put blackberries in to make up the filling. We used about 2.5 cups berries half cup sugar and about a teaspoon constarch. I was worried about being soggy. We put the blackberry mixture on top of the crust and spread the lemon on top and the crumble top. I then prayed for about 20 minutes cause I wanted them to turn out good for her. THEY DID!
It was a good time to tell the kids how I messed up by not checking for all the ingredients, which they were kind enough to tell their parents!
I kept wondering if maybe you did this and there was a REAL recipe. I think I could have used more berries but was worried about the soggy factor.
★★★★★
So easy to make and delicious!
★★★★★
I just made this for my family and they all LOVED IT. I thought it was going to be too lemony but it was just the right amount.
★★★★★
Made this yesterday for the first time. Absolutely delicious! Thanks, Sally!
I’ve made this recipe before and loved it! I’m wondering if the filling can have cherries added? I read in another comment you said some fruits can release a lot of juice and it might not set well. Do you think it could work with cherries? If so, how would I go about that?
★★★★★
Hi Nicole, I think adding some fresh cherries would be fine. I would halve or quarter them and sprinkle on top of the filling before adding the crumble on top.
Why would you go to all this trouble to make this in an 8×8 pan….not worth my time!
There are only 2 of us, so it’s more than enough. If the grandkids were visiting or taking it to church, then I double it.
I want to make it with a graham cracker crust. I wonder if the top crust would be thick enough?
Hi Ree, you could definitely try making this with a graham cracker crust. For the topping, you could make half of the crumble as written. Hope this helps, and please do let us know how it turns out for you!
Could you add fresh fruit like raspberries or blueberries to this before layering in the lemon filling?
Hi Colleen, we haven’t tested it before, so we’re unsure how the bars would set with those additions. Raspberries in particular can release a lot of liquid, so we fear the bars wouldn’t set quite the same. If you decide to do any experimenting, please do let us know how it goes!
I am disappointed in the double crust. I followed your recipe to the tee. Saved the dough for the next day and it was hard and crumbly and couldn’t roll it. I had to patch it on the pot pie.
Hi Gloria! Arę you referring to our chicken pot pie recipe? If your pie dough was too dry, it may have been under-hydrated. Make sure to spoon and level your flour when measuring, and try adding just a bit more water to the dough next time.
This is a new favorite recipe! The creamy lemon filling pairs so well with the oatmeal crumble and it’s an easy recipe to make. I took it to the church potluck and it was definitely a hit. Will make this again for sure!
★★★★★
Can I use another flavor or type of filling? For example, could I replace the lemon juice/zest with vanilla extract? If so, how much vanilla extract? Thank you.
Hi Meg! You could replace the lemon juice/zest with other citrus, but we haven’t tested anything beyond that. Let us know what you try!
My family loves this recipe! It is so easy and quick! Thank you so much for your website, I am constantly looking and deciding what to make next!
Thanks you so much for making our recipes, Teri!
I love the recipe but want to figure out how to make it less sweet and more tart. Would evaporated milk sweetened by taste with brown sugar work. Doubling the lemon helped (doubled the recipe and used 6 lemons). Overall- absolutely delicious recipe in terms of layers- just want more lemon and less sugar flavor (used lemons from my tree). Thank you!
Hi Skye, unfortunately, 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, so that might be your best bet for trying a less-sweet version.) You could also try a bit more zest for a more lemony version. Let us know what you try!
I added lemon curd to mine to tame the sweetness a touch and it worked great and there were no issues with consistency!
★★★★★
These are freaking amazing. I used evaporated milk and added sugar and an egg to it because I didn’t have sweetened condensed milk an it turned out great
★★★★★
I made this for the first time this weekend. It was such a huge it. Very simple to make and delicious!!
★★★★★
Sally, I have extra lemons and am excited to try this recipe! Its sounds delicious and different from the traditional lemon bars, and your explanations always teaches me something new! Thanks so much! In addition, I have a request. You often give a recipe for store bought seasonings or boxed ingredients we can make at home for a fresher substitute without the preserves. I really appreciate that!! Would you feature some your favorites homemade substitutes? I would love to have them all in one place, in addition to the recipe you originally used them in? Thanks again!
★★★★★
Can I substitute gluten free flour in your Oatmeal lemon crumble bars?
Hi Jan, 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!
Great! I make these gluten-free using GF Jules flour and they turn out great! I also add a little extra lemon zest. Very easy to make.
★★★★★
Made these for a book club potluck and they were a hit! So easy to throw together and absolutely delicious. A keeper!
★★★★★
Sooo delicious and so easy to make! The whole family loved it! I’ll definitely be making it again!
★★★★★
This recipe was excellent. I had very little energy but wanted to bake something and these for the bill perfectly. I was shocked at how easily they came together and how tasty they are! The crumble on top mixed with the creamy filling that isn’t overly sweet make these the perfect treat! I think I will be doubling the recipe and making them for Mother’s Day dinner! Thanks!!
★★★★★
So glad you loved these, Tamara!
seems like a delicious recipe, unfortunately it was a total disaster for us. i was so excited that this was egg free, due to an egg allergy in the house. but i didn’t see the note about substitutions until after the fact used sweetened condensed *coconut* milk due to a dairy allergy. it smelled amazing but sadly did not set at all. would love to see an update with a way to make this non-dairy! the original version looks delicious.
I made these added 3Tbs of cream cheese to the filling they were amazing
★★★★★
Perfect pick me up on this rainy day, here in Texas. I definitely should have added a tad bit more to the bottom crust but it was still delicious!
Absolutely delicious!! You never disappoint!!
★★★★★
Perfect recipe! So easy & flavorful – my son asked me to make them again for his 16th birthday. Thanks Sally =^)
★★★★★
I doubled the recipe and made as stated. They came out perfect. My husband and his co-workers absolutely loved them. I also made a “Mounds” type bar with coconut and dark chocolate as the filling, again another hit out of the park. I will be experimenting with different fillings. Thanks for sharing such a fantastic base recipe.
★★★★★