Buttery, golden, and bursting with bright citrus flavor, these Lemon Crumb Bars are the easiest lemon bars recipe you’ll ever make — no fancy equipment, no fuss, just pure lemony magic in every bite.
Okay, real talk — I made these on a whim one Sunday afternoon when I had a fridge full of lemons and zero patience for anything complicated, and they’ve been on permanent rotation ever since. Think buttery oat crumble hugging a silky, tangy lemon filling that tastes like sunshine had a bake sale. You’re going to love them.
Table of Contents
Why You’ll Be Obsessed With This Lemon Crumb Bar Recipe
These aren’t your average lemon desserts. We’re talking a soft, golden oat-and-butter crust on the bottom, a dreamy condensed milk lemon filling in the middle, and more of that crumbly goodness scattered right on top.
It’s a dessert bar recipe that somehow manages to feel both indulgent and refreshing at the same time — which, honestly, is a rare and beautiful thing.
The filling uses sweetened condensed milk and fresh lemon juice, so it sets up perfectly without being fussy. No water baths, no tempering, no drama. Just mix, layer, bake, and try not to eat the whole pan.
Lemon Crumb Bars
Equipment
- Mixing bowl
- Whisk
- 8×8-inch baking pan
- Oven
Ingredients
Oat Crumble (Crust + Topping)
- 1.25 cups all-purpose flour
- 1.25 cups rolled oats old-fashioned
- 0.5 cup granulated sugar
- 0.5 cup brown sugar packed light
- 0.75 cup unsalted butter melted
- 1 tsp vanilla extract
- 0.5 tsp salt
- 0.5 tsp baking soda
Lemon Filling
- 1 can sweetened condensed milk 14 oz
- 0.5 cup fresh lemon juice
- 2 tbsp lemon zest finely grated
- 2 egg yolks large
Instructions
- Preheat oven to 175°C (350°F) and grease an 8×8-inch baking pan.
- In a bowl, whisk together flour, oats, salt, and baking soda. Add sugars, melted butter, and vanilla, mixing until crumbly.
- Press half of the crumble mixture firmly into the pan to form the crust. Bake for 15 minutes until lightly golden.
- In another bowl, whisk together sweetened condensed milk, lemon juice, lemon zest, and egg yolks until smooth.
- Pour the lemon filling over the warm crust, then sprinkle the remaining crumble mixture evenly on top.
- Bake for 20–22 minutes until the top is lightly golden and the filling is just set.
- Cool completely at room temperature, then refrigerate for at least 2 hours until firm.
- Slice into bars and serve chilled or at room temperature.
Notes
What You’ll Need
Here’s everything that goes into these beauties, all laid out nice and tidy:
For the Oat Crumble (Crust + Topping)
| Ingredient | Amount |
|---|---|
| All-purpose flour | 1¼ cups |
| Old-fashioned rolled oats | 1¼ cups |
| Granulated sugar | ½ cup |
| Packed light brown sugar | ½ cup |
| Unsalted butter, melted | ¾ cup |
| Vanilla extract | 1 tsp |
| Salt | ½ tsp |
| Baking soda | ½ tsp |
For the Lemon Filling
| Ingredient | Amount |
|---|---|
| Sweetened condensed milk | 1 can (14 oz) |
| Fresh lemon juice | ½ cup |
| Finely grated lemon zest | 2 tbsp |
| Large egg yolks | 2 |
A quick note on the lemons: Please use fresh. Bottled lemon juice will technically work but it tastes flat and a little sad compared to the real thing. You’ll need about 3–4 good-sized lemons for both the juice and the zest.
Let’s Make These Lemon Crumb Bars
Step 1: Get Your Pan Ready and Preheat
Heat your oven to 350°F (175°C) and give an 8×8-inch baking pan a generous spritz of baking spray. You want every corner coated so nothing sticks when you’re trying to get those clean, pretty slices later. This is not the step to rush.
Step 2: Make the Crumble Base
In a large bowl, whisk together the flour, oats, salt, and baking soda. Stir in both sugars, then pour in the melted butter and vanilla extract. Mix it all together until it looks like damp, clumpy sand — in the best possible way. It should hold together when you press a bit between your fingers.
Tip: Don’t overmix! You want a crumbly texture, not a paste.
Step 3: Press In the Crust
Take half of your crumble mixture and press it firmly and evenly into the bottom of your prepared pan. Really get in there with your hands or the bottom of a flat measuring cup — a packed, even layer means a sturdy base that holds up to the filling without crumbling apart when you slice it. Pop that into the oven for 15 minutes.
It should look lightly golden around the edges when it comes out. Your kitchen is going to smell absolutely incredible right about now.
Step 4: Whisk Up the Lemon Filling
While the crust is doing its thing in the oven, grab a medium bowl and whisk together the sweetened condensed milk, lemon zest, fresh lemon juice, and egg yolks. The mixture should be smooth, silky, and a beautiful pale yellow. Take a small sniff — that lemon aroma is something special.
It’ll look a little thin, but don’t worry. It firms up beautifully once baked.
Step 5: Layer and Top
Once your crust is out of the oven, pour the lemon filling evenly over the hot crust. Then take that remaining crumble mixture and sprinkle it all over the top. Don’t press it down — you want those lovely craggy bits to stay light and crumbly.
Step 6: Back Into the Oven
Bake for another 20–22 minutes, until the top is lightly golden and the filling looks just set — it might still have a tiny jiggle in the center, and that’s perfectly fine. It’ll firm up as it cools.
Let the bars cool completely at room temperature before moving them to the fridge. I know it’s hard. I know. But it’s worth the wait.
Step 7: Chill, Slice, and Serve
Once they’re fully cooled, refrigerate until firm — at least a couple of hours, ideally overnight. For the cleanest slices without any filling ooze, you can even pop them in the freezer for 20–30 minutes before cutting. Use a sharp knife and wipe it clean between cuts. Gorgeous every time.
Optional Step: White Chocolate Dipped Bars (Yes, Really)
This is entirely optional but also wildly delicious — dip the bottom half of your frozen bars into melted white chocolate, set them on a wax paper-lined baking sheet, and refrigerate until the chocolate is firm. It adds a creamy sweetness that plays so well with the tart lemon filling. Total showstopper for parties or gifting.
If you love creative lemon desserts like this, you’ll definitely want to check out this gorgeous mini lemon tart with lilac meringue — it’s stunning on a dessert table.
Expert Tips, Variations, and Troubleshooting
Get the Best Results Every Time
Use room-temperature egg yolks if you can — they blend into the condensed milk more smoothly. Also, zest your lemons before you juice them. (Ask me how I learned that the hard way.) And truly, don’t skip chilling before cutting. Warm lemon bars are tasty but messy.
Make It Your Own
Want to switch things up? Here are a few fun directions to take this dessert bar recipe:
Lime version: Swap the lemon juice and zest for lime. Same method, totally different vibe — almost like a key lime bar. Obsessed.
Berry swirl: Drop a few spoonfuls of raspberry or blueberry jam onto the filling before adding the crumble topping and swirl gently with a toothpick. The tartness of the berries and the lemon is chef’s kiss.
Gluten-free swap: Use a 1:1 gluten-free flour blend and certified GF oats. Works beautifully.
Coconut crumble: Replace ¼ cup of the oats with shredded coconut for a tropical twist on the topping.
Troubleshooting
Filling too runny after baking? It probably needed a few more minutes in the oven. The edges should look fully set. Make sure you’re refrigerating long enough before slicing, too — at least 2 hours.
Crumble too dry or not sticking together? Add a teaspoon more melted butter. The humidity in your kitchen can affect how the mixture comes together.
Bars too tart? Next time, dial back the lemon juice by a tablespoon or add an extra tablespoon of condensed milk to the filling.
Storage Guide
| Method | How Long |
|---|---|
| Airtight container in the fridge | Up to 5 days |
| Individually wrapped in the freezer | Up to 2 months |
| Room temperature (briefly, for serving) | Up to 2 hours |
Reheating and No-Waste Ideas
These bars are best served cold or at room temperature — no reheating needed or recommended. The lemon filling is meant to be cool, creamy, and refreshing.
If you have crumble mixture left over (or your bars break during cutting — it happens to the best of us), toss the crumbles over vanilla ice cream or mix them into yogurt. Absolutely no waste, all of the deliciousness.
You can also crumble leftover bars over a bowl of fresh berries for an almost-effortless summer dessert that looks way fancier than it is. Pair it alongside something savory like this sourdough pesto grilled cheese for the ultimate laid-back lunch-and-dessert combo.
Nutritional Information (Per Bar, Based on 16 Servings)
| Nutrient | Approximate Amount |
|---|---|
| Calories | 285 kcal |
| Total Fat | 12g |
| Saturated Fat | 7g |
| Carbohydrates | 41g |
| Sugar | 27g |
| Protein | 4g |
| Fiber | 1g |
| Sodium | 135mg |
Note: Nutritional values are estimates and will vary based on specific brands and portion sizes.
Lemon Crumb Bars FAQs
Can I use bottled lemon juice instead of fresh?
You can in a pinch, but fresh lemon juice really does make a noticeable difference here. The flavor is brighter and more vibrant, and the zest (which you can only get from fresh lemons) adds an aromatic depth that bottled juice just can’t replicate. If fresh lemons are available, go for it — it’s worth the extra five minutes of squeezing.
Can I double this recipe for a larger batch?
Absolutely — just use a 9×13-inch pan and keep an eye on the baking times. The crust bake time will stay similar, but the final bake with the filling may need an extra 3–5 minutes. Check for a lightly golden top and set edges as your cues.
Do these lemon crumb bars need to be refrigerated?
Yes, definitely. The egg yolk and condensed milk filling needs to stay cold for both food safety and texture. They’re honestly better cold anyway — that cool, creamy lemon filling is what makes this lemon bars recipe so refreshing.
Can I make these ahead of time?
These are actually a great make-ahead dessert! Bake them the day before, refrigerate overnight, and slice them fresh the next day. The flavors even deepen a bit after sitting, so day-two bars might be even better than day-one.
Why do my bars fall apart when I slice them?
They probably need more time in the fridge — or better yet, try the freezer trick. Chill the whole uncut pan in the freezer for 20–30 minutes, then slice quickly with a clean, sharp knife. This is the move for clean, bakery-worthy slices every single time.
Let’s Talk About That First Bite
There’s something genuinely magical about pulling a pan of Lemon Crumb Bars out of the fridge, slicing them into neat little squares, and watching someone take that first bite. The crumble holds its shape just enough, the lemon filling is silky and perfectly tart-sweet, and the whole thing just works in a way that feels way more impressive than how easy it actually was to make.
These lemon desserts are the kind of thing you bring to a potluck and come home with an empty pan and three people asking you for the recipe. If you love easy, crowd-pleasing dessert bar recipes, you might also adore these honey peach cream cheese cupcakes — another guaranteed crowd-pleaser that hits that same cozy-but-special sweet spot.
Go Make These Already!
Seriously — if you’ve been on the fence, this is your sign. These Lemon Crumb Bars are the kind of recipe that earns a permanent spot in your rotation after the very first batch. They’re simple enough for a casual weeknight bake and impressive enough to bring anywhere.
When you make them (not if — when), I’d love to hear how they turned out! Drop a comment below, leave a star rating, and if you’re feeling fancy, save this recipe to your Pinterest boards so you (and your friends!) can find it again easily. Happy baking! 🍋
