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 this dessert recipe 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.
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 (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 | Citrus Zester | Citrus 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.
Hi Sally, I have a friend that can not have dairy. What are you thoughts on using full fat coconut milk instead of sweetened condensed milk?
Hi Mary, coconut condensed milk would be your best bet for a dairy-free option, although we haven’t tested it ourselves. Let us know if you do!
I like this recipe a lot . Can you mix ricotta cheese with the condensed milk to cut down the sweetness from the condensed milk?
Hi Marciacay, we haven’t tested it, but we fear adding the ricotta will compromise the setting of the filling.
Thanks Lexi. I appreciate your response. Any thoughts on how to cut down on the sweetness from the condensed milk?
My husband, who is not a big lemon fan said, “These are really good”. That is a BIG compliment. They are delicious. Another hit.
This is the third time I’ve made these lemon bars. They’re delicious and easy to make. However, I must agree with another poster who said there is too much flour/oat crumble mixture for the size of the pan and the amount of filling. I always seem to end up with more topping than I need. I feel that Sally and her staff should revise this recipe and reduce the amount of crumble/base for this recipe. Even when I used more of it, I still had way too much for the topping.
Hi Aly, thank you for reporting back. I haven’t experienced that issue before; I wonder if you could be using a bit more in the crust? Let me double check my notes. I appreciate your feedback and am glad you enjoy them.
Hi! Wondering if this can be made without the lemon in the filling? Looking for something more like the little Debbie oatmeal cream pies
Hi Megan, here is our oatmeal creme pies recipe instead!
Great recipe… thanks for sharing…. I tweaked it a little and added cranberries to the filling ….awesome !,, next time maybe raspberries or blueberries… they all go well with lemon
Made this recipe and it is so good.I followed your advice and didn’t overbake ..It was perfect.Will definitely make this again very lemony delicious.
I made exactly as directed. The bottom crust was great. The top was so crumbly that I actually didn’t serve them for fear of the crumbs getting all over the place (which they did when my son ate them up!). I wonder if adding in more butter would cause the top crust to come together a but more and not be dusty and fall all over. I will try again.
Hi Susan, The top of these bars is pretty crumbly! How did you measure your flour? Be sure to spoon and level (or weight measure) to ensure just the right amount — too much could potentially make these overly crumbly.
Made as directed, not a strong lemon flavor. Will not be making this again, but love other recipes on this site.
Hi Christine, thanks for trying these and for the feedback. If you ever want to try them again, some extra lemon zest and even a splash of lemon extract can help.
Delicious!!!! I used cup4cup to make them GF and added the zest of a second lemon.
We loved the oatmeal lemon bars! Made them two weeks ago and making them again tomorrow! It’s an upgrade to the quintessential lemon icebox pie.
Hi Sally I absolutely love your baking recipes.
You always explain why you do something a certain way. Love that about you. I made your Oatmeal Lemon Crumble Bars for the first time and they turned out great. Mom and I love it especially adding rind of 2 lemons instead of 1. It tasted heavenly. Thank you for this recipe.
Hi Sally! The condensed milk/juice/zest is staying very liquidy. I tried with a hand whisk and the kitchenaid using a whisk attachment. Any ideas what I could be doing wrong? I used the whole can and made sure it is sweetened condensed milk. But it is my first time working with this.
Hi Serina, I’m sorry to hear you’re having trouble with this! My best guess is that there is a little too much lemon juice… are you using full-fat sweetened condensed milk? It should be a pourable consistency, which will soft-set in the fridge.
Great recipe. The bars are so much better when chilled. Great summer treat.
Do you think that I could substitue lime for lemon (I would add a few drops of green food colouring). Sometimes I like to have a tray with lemon and lime goodies.
Hi Allyson, you can absolutely use limes here instead. Enjoy!
These turned out great! My personal preference is for a stronger lemon taste (hence the 4 stars) so I’ll likely stick with traditional lemon bars going forward, but this is a good recipe.
Was wondering if you could double the filling before baking.
Hi Margaret, You can 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.
Does this recipe need eggs for the filling?
Hi Grace, this recipe does not need eggs in the filling, no. Let us know if you give them a try!
You mentioned heavy cream can be used as substitution for condense milk, what would be the measurements?
Hi Ad, you can use the same amount (14 oz.). Keep in mind that you’ll have to test with varying amounts of sugar since both are unsweetened.
I love this recipe and made it as written with the exception of doubling it. It was so delicious and received rave reviews from everyone who tried it. I just made it for the second time this week lol but I added blueberries to it for a twist and it didn’t disappoint.
I love all the recipes on this site and my web browser brings up this site first when I’m searching for new recipes to try!
Could I replace the lemon juice/zest with orange?
Hi Serina, that should work just fine!
Can I use coconut or low fat condensed milk? I can’t half full fat. Sounds scrumptious
Hi Lexi, coconut condensed milk would be your best bet, although we haven’t tested it ourselves. Let us know if you do!