Why You’ll Love This Recipe
If you’re a fan of desserts that blend fresh fruit flavor with a comforting, home-baked feel, these bars will be a favorite. The oatmeal crumble base and topping add warmth and chewiness, while the lemon layer brings a burst of sunny brightness. They’re simple to make, look beautiful when sliced, and travel well—making them perfect for picnics, potlucks, or just enjoying with a cup of tea at home.
Ingredients
(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)
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All-purpose flour
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Rolled oats
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Brown sugar
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Granulated sugar
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Unsalted butter
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Baking powder
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Salt
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Fresh lemon juice
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Lemon zest
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Eggs
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Cornstarch
Directions
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Preheat the oven to 350°F (175°C). Line an 8×8-inch baking dish with parchment paper, leaving some overhang for easy removal.
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In a large mixing bowl, combine flour, rolled oats, brown sugar, baking powder, and salt.
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Cut in the butter using a pastry cutter or your hands until the mixture resembles coarse crumbs.
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Press about two-thirds of the crumble mixture evenly into the bottom of the prepared baking dish to form the base.
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In a separate bowl, whisk together granulated sugar, eggs, lemon juice, lemon zest, and cornstarch until smooth.
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Pour the lemon mixture evenly over the crust.
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Sprinkle the remaining crumble mixture over the top.
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Bake for 30–35 minutes, or until the top is lightly golden and the lemon filling is set.
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Allow the bars to cool completely in the pan before lifting them out with the parchment and slicing into squares.
Servings and timing
This recipe makes about 12 bars.
Prep time: 15 minutes
Bake time: 30–35 minutes
Cooling time: 1–2 hours
Variations
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Use Meyer lemons for a sweeter, more floral citrus flavor.
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Add a handful of shredded coconut to the crumble for a tropical twist.
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Swap half of the rolled oats for chopped nuts like almonds or pecans for extra crunch.
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Replace lemon with lime for a tangy twist.
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Drizzle with a simple powdered sugar glaze once cooled for extra sweetness.
Storage/Reheating
Store the bars in an airtight container at room temperature for up to 3 days or in the refrigerator for up to 1 week. For longer storage, freeze them for up to 2 months, separating layers with parchment paper. Thaw at room temperature before serving. These bars are best enjoyed at room temperature and do not require reheating.
FAQs
Can I use bottled lemon juice instead of fresh?
Fresh lemon juice is highly recommended for the best flavor, but bottled can be used in a pinch.
Can I make these bars gluten-free?
Yes, simply substitute a gluten-free all-purpose flour blend and use certified gluten-free oats.
Can I double the recipe?
Absolutely—just use a 9×13-inch pan and adjust baking time slightly, adding a few more minutes if needed.
How do I know when the bars are done baking?
The top should be lightly golden and the lemon filling set without being jiggly in the center.
Can I make these ahead of time?
Yes, these bars taste even better the next day once the flavors meld.
What type of oats should I use?
Old-fashioned rolled oats work best; avoid instant oats as they can become mushy.
Can I use salted butter?
Yes, but reduce the added salt in the recipe by half.
Why did my lemon layer turn out runny?
This may happen if the bars are underbaked or if too little cornstarch was used.
Do I need to refrigerate the bars?
They can be stored at room temperature for 2–3 days but should be refrigerated for longer storage.
Can I add berries to the lemon filling?
Yes, blueberries or raspberries make a delicious addition, but they may add extra moisture, so bake a few minutes longer.
Conclusion
Lemon oatmeal crumble bars are a cheerful, citrus-packed treat that combines the bright tang of lemon with the hearty comfort of an oat crumble. They’re easy to make, versatile to customize, and perfect for sharing—or keeping all to yourself. With their sunny flavor and satisfying texture, they’re sure to brighten up any day.
Lemon Oatmeal Crumble Bars
Bright, zesty, and irresistibly sweet, these Lemon Oatmeal Crumble Bars are the perfect balance of tangy lemon curd and buttery oat crumble. Easy to make and ideal for dessert or snack, they’re a sunny treat in every bite.
- Prep Time: 15 minutes
- Cook Time: 35 minutes
- Total Time: 50 minutes
- Yield: 16 bars
- Category: Dessert
- Method: Baking
- Cuisine: American
- Diet: Vegetarian
Ingredients
- 1 cup unsalted butter, melted
- 1 cup brown sugar, packed
- 2 cups old-fashioned rolled oats
- 2 cups all-purpose flour
- 1 tsp baking powder
- 1/2 tsp salt
- 1 jar (about 12 oz) lemon curd (homemade or store-bought)
- 1 tbsp lemon zest (optional, for extra zing)
- Powdered sugar, for dusting (optional)
Instructions
- Preheat oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper.
- In a large mixing bowl, combine melted butter, brown sugar, oats, flour, baking powder, and salt until crumbly.
- Press half of the mixture firmly into the prepared pan to form the base.
- Spread lemon curd evenly over the base. Sprinkle with lemon zest if desired.
- Crumble the remaining oat mixture over the lemon layer, pressing lightly.
- Bake for 30–35 minutes, or until golden brown.
- Cool completely in the pan before slicing into bars. Dust with powdered sugar if desired.
Notes
- For a stronger lemon flavor, mix extra zest into the curd before spreading.
- Bars store well in an airtight container for up to 5 days at room temperature or 1 week refrigerated.
- Can be frozen for up to 2 months; thaw at room temperature before serving.
