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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!

creamy lemon oat crumble bars with lemon slices

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!

two creamy lemon crumble bars on a green plate

You Need 9 Ingredients Total:

ingredients on marble counter including lemons, oats, sweetened condensed milk, brown sugar, and butter
  1. 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. 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.

crumble crust and topping mixture in bowl and shown in bottom of baking pan

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.

pouring lemon filling on crust and shown again with crumble topping

3 Success Tips

Though it’s a really easy recipe, here are 3 success tips that have helped me perfect these creamy lemon bars.

  1. 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.
  2. 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.
  3. 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.

stack of 3 lemon crumble bars
Print
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two creamy lemon crumble bars on a green plate

Oatmeal Lemon Crumble Bars

  • Author: Sally
  • Prep Time: 15 minutes
  • Cook Time: 38 minutes
  • Total Time: 2 hours (includes cooling)
  • Yield: 16 bars 1x
  • 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

Scale

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

  1. Preheat oven to 350°F (177°C). Line an 8-inch square pan with parchment paper.
  2. 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.
  3. 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.
  4. Meanwhile, make the lemon filling: Whisk sweetened condensed milk, lemon juice, and lemon zest together. Mixture will be thick.
  5. Pour and spread filling over pre-baked crust (while crust is hot). Sprinkle the remaining crumble mixture on top.
  6. 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.
  7. Lift the bars out using the parchment paper overhang on the sides. Cut into squares.
  8. Cover leftover bars and store at room temperature for up to 2 days or in the refrigerator for up to 1 week.

Notes

  1. 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.
  2. 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.
  3. 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.
  4. 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

Reader Questions and Reviews

  1. I made these this afternoon. They are so good!! Thank You Sally for a very tasty Lemon Bar that were so easy to make. A keeper of a recipe for sure!!

  2. DELICIOUS! Quick to make and easy enough to make with my 5 year old. Will make again!

  3. Hi sally! Just wondering, how would I be able to incorporate lemon curd here? I have a jar of it sitting in the cupboard.

    1. Hi Eva, you could drizzle the lemon curd on top of the finished bars. We don’t recommend incorporating it in the lemon creme layer, as it might not set as well with the added liquid. Hope this helps!

    2. Hi Eva, today I try the lemon curd mixed in the lemonmix. It works and was very delicious.
      Thank you Sally for all the wonderful recipes.
      Greetings from Germany

  4. Simple to make and I had all the necessary ingredients to make half a batch (just for myself)! I’m wondering if I could make the bottom and top layers but replace the middle with a thickened blueberry filling next time. Do you think this would be possible?

  5. These were fantastic! Made them with my three-year-old and they are perfection. Love this alternative to classic lemon bars and the 8×8 size.

  6. Wonderful. Warm, it is like a delicious lemon crumble. Cold, the bars are even better, with delightful variety of textures. Also amazing that it’s egg-free!

  7. Hi Sally, I made these bars last weekend for some out of town guests and they came out perfect! I love the lemon flavor and the oatmeal crust and topping really made them great. Very simple to make! Thank you!

  8. I must have done something wrong….my top crust was very crumbly.; is this normal? I’m wondering if my butter wasn’t mixed enough. Any ideas would be appreciated.

    1. 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.

      1. I measured as suggested, spoon and level. I used a Kitchen Aid hand mixer and wasn’t thrilled with how it mixed the sugar and butter since it seemed dry. Do you think using my big Kitchen Aid would have made a difference in the consistency of the butter/sugar mixture because I had “big crumbs.” Thx!

  9. Delicious and so easy to make. I will definitely be making these again. Thank you for another great recipe, your recipes are always the first place I look when baking!

  10. Since my son and I can’t have milk, I tried making these with sweetened condensed coconut milk (available at grocery stores). The bars set up perfectly. The lemon flavor wasn’t as strong as I like, so I drizzled a little lemon glaze over the top to amp up the lemon flavor. I might try a version with pineapple juice and toasted coconut.

  11. These were amazing!! I followed the recipe exactly and they were perfect. They even tasted better after a few days!

  12. Hi Sally. Is it possible to make these bars by assembling them & baking once instead of baking the bottom layer, adding the filling, adding the top layer & baking again? Please let me know. Thanks.

    1. Hi Harry, for best results, we recommend following the recipe as written. It’s important to give the bottom crust time to bake before adding on the filling and top crumble. Hope you enjoy these bars!

  13. The best lemon bars yet. It’s helpful to read the Notes and Tips before beginning. Definitely do NOT use a 9 inch pan. I used the recommended 8 inch and the bars had a good proportion of filling to topping/crust. When I sprinkled the topping on the filling, I lightly pressed it into the filling….the topping stayed on top of the filling once I cut the bars. I wasn’t sure about using the parchment paper, but I’m glad I did. Once the bars cooled it was so easy to just lift out and cut. I had to work a little to get the paper to fit into the corners of the pan. I baked the bars the minimum amount of time, and they turned out custardy and firmed up nicely. The only change I made was to add 1/2 T. lemon extract to get a little more lemon flavor.

  14. I notice you can use old-fashioned or quick oats. Do you have a preference? Thank you.

    1. Hi Sheila, we don’t have a preference here and use both when making these bars. If you tend to prefer the size/texture of one over the other, we’d recommend using those. Hope you love the bars!

  15. Have you ever experimented with whole wheat or white whole wheat flour in this recipe?

    1. Hi Sara, we have not tested this recipe that way, but we’d expect the crumble to be a bit drier with that substitution. If you do decide to try it, we’d love to know how it goes!

    1. Hello! No, we don’t recommend oil in these bars. Best to stick with butter – oil won’t properly cream with the sugar and lead to loose and oily bars.

  16. Oh, my stars, these are good! I may have been a little cautious with the crust because I wanted to be sure I had enough for the crumble. Next time, I will be more generous… But it all ended up in the bars. They were delicious slightly cooled off ( I couldn’t wait!) and chilled as well. This one is definitely going in the rotation. Thank you for such a wonderful treat.

  17. Hello Sally,
    what can be used to substitute in place of sweetened condensed milk?
    thanks!

    1. Hi Brian, There are no successful replacements for sweetened condensed milk in this particular recipe—it’s really the key ingredient. See recipe notes for more details if you’re interested!

  18. Wow-wow good! Followed the recipe, spoon measured etc. Perfect indulgence! Great, easy, refreshing chilled delight. This will be my new goto sharable. Zesty lemon with the oats and brown sugar makes for a fantastic combination of yum! Amazingly simple to make! Hubby enjoyed. Thanks!!

  19. I’m not exaggerating when I say that these are the best lemon bars that I’ve ever had. So good. I wish I could rate this recipe a 1,000.

  20. Made this recipe originally following ingredients and method and they were delicious. Vegan daughter was very envious so I made some with flora plant butter and vegan condensed milk. Just as delicious but lemon centre more like lemon curd and more sticky but she loved them

  21. Help! Just doubled this recipe and realized I don’t have a second can of condensed milk. I already baked the crust…will it be okay to leave it until I return from the store and put the filling in when it’s not hot? Or maybe just bake it for 1-2minutes to heat it up? Thanks!

    1. Hi Nicole, yes, just pop the crust back in the oven for a minute or two to slightly heat it up (but try not to over bake it) — should be just fine!

    1. Hi Sandra! We haven’ tested it, but solid coconut oil could work in place of the butter. The bars may taste greasier and obviously taste like coconut as well. Let us know if you give it a try!

  22. Hi Sally, could I add fresh blueberries to this recipe somehow? Or even blueberry or raspberry jam between the layers? Thank you in advance!

  23. I added quite a bit more zest than the recipe calls for because I LOVE lemon flavor!! Super delicious still and a lovely tangy lemony flavor! Great recipe as always!

    1. Yes! See recipe notes for freezing instructions. Enjoy!

  24. I didn’t have an 8×8 pan so I tried using a muffin tin instead (with paper liners/cups) and it worked great! Knowing they’d take less time, I watched them carefully and baked the bottom crust for maybe 9 minutes. (I opened the door a few times to check as I couldn’t see the tops through the glass.) At that point the crust was a little hardened but not browned. I then added the filling and topping and baked for about 18-19 minutes, checking at 15. The tops were just beginning to brown and the bottom was just about perfect – browned enough to hold the filling, but not at all burned.
    I found these super sweet, almost too sweet, and I like sweet! I think next time I’ll either use a little less condensed milk or just eat them with coffee or tea.

  25. When I tell you that these Lemon Bars are “out of this world good,” I really mean it! Sally again has created a masterpiece from only a few ingredients! The added lemon peel takes it over the top! The hardest part of this recipe was waiting for it to cool. We love it!!!

  26. This recipe is FANTASIC! I followed the directions exactly as written. I loved the fresh flavor of the lemon layer as well as the change from classic lemon bars by using the oat crust and topping. It was a quick and easy recipe that everyone in my family enjoyed. I will absolutely make it again since I love a tasty, naturally flavored lemon dessert. I found that despite purchasing nicely sized lemons, in order to get to one tablespoon of zest (as stated in the directions), I needed the zest of two lemons. I would advise measuring it out rather than just going with “about one lemon.” We tried them slightly before they had completely cooled and thought they were great. We stored them in the fridge and also loved them chilled. As usual, Sally is my go-to for recipes, and this one did not disappoint! Thanks Sally!

  27. This recipe is amazing! Easy to follow, easy cleanup, and DELICIOUS results. I froze the bars and have been sharing them with friends. Can’t wait to make them again!

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