Lemon Crumb Bars with a Buttery Streusel Topping

Hi I'm Merry

Everyday Culinary Delights👩‍🍳

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There’s something about the scent of fresh lemons that instantly transports me back to my grandmother’s kitchen. As a child, I spent countless summer afternoons perched on a stool, watching her zest and juice lemons with effortless precision. She believed that citrus desserts had a way of brightening the spirit, and I couldn’t agree more.

Her lemon bars were legendary—tangy, sweet, and with just the right amount of richness. But as I grew older, I found myself wanting something with a bit more texture, a balance between smooth and crumbly. That’s how these Zesty Lemon Oat Bars were born—a recipe that combines the comforting chewiness of oats with the vibrant brightness of fresh lemons.

This dessert is simple to make yet incredibly satisfying. The oat crust provides a buttery, slightly crunchy base, while the creamy lemon filling delivers a bold citrus punch. Topped with a golden crumb layer, every bite is a perfect harmony of flavors and textures. Whether you serve these for a family gathering, a summer picnic, or as a midday treat with coffee, they’re sure to impress.

Why You’ll Love These Lemon Oat Bars

These bars are a must-try for anyone who loves the refreshing taste of lemon in a dessert that is both hearty and satisfying. Here’s why:


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1. A Perfect Balance of Sweet and Tart

The combination of sweetened condensed milk and fresh lemon juice creates a creamy, tangy filling that pairs beautifully with the rich, buttery oat crust.

2. Incredible Texture

The oat base and crumbly topping provide a satisfying contrast to the smooth lemon layer. Unlike traditional lemon bars with a shortbread crust, these bars offer an extra dimension of chewiness.

3. No Fancy Ingredients Required

Everything you need is a pantry staple—flour, oats, butter, sugar, and fresh lemons. This makes it an easy go-to recipe whenever a lemon craving strikes.

4. Great for Any Occasion

These bars are perfect for:

  • Brunches or afternoon tea—a light yet indulgent treat.
  • Potlucks and gatherings—easy to make and transport.
  • A refreshing dessert after dinner—not too heavy, but just rich enough.

Zesty Lemon Oat Bars: A Sweet and Tangy Treat

Ingredients for a Perfect Bite

For the Oat Crust & Topping:

  • 1 ¼ cups all-purpose flour
  • 1 ¼ cups old-fashioned rolled oats
  • ½ teaspoon salt
  • ½ teaspoon baking soda
  • ½ cup granulated sugar
  • ½ cup packed light brown sugar
  • ¾ cup unsalted butter, melted
  • 1 teaspoon vanilla extract

For the Luscious Lemon Filling:

  • 1 (14 oz) can sweetened condensed milk
  • 2 tablespoons finely grated lemon zest
  • ½ cup fresh lemon juice
  • 2 large egg yolks

Step-by-Step Directions to Citrus Bliss

Step 1: Prepare the Oat Crust

  1. Preheat the oven to 350°F (175°C) and line an 8×8-inch baking pan with parchment paper.
  2. In a large bowl, mix together the flour, rolled oats, salt, baking soda, granulated sugar, and brown sugar.
  3. Pour in the melted butter and vanilla extract, stirring until the mixture resembles a crumbly dough.
  4. Press two-thirds of the mixture evenly into the bottom of the prepared pan to form the crust. Bake for 12-15 minutes until lightly golden.

Step 2: Create the Lemon Filling

  1. In a medium bowl, whisk together the sweetened condensed milk, lemon zest, lemon juice, and egg yolks until smooth.
  2. Pour the lemon filling over the pre-baked crust, spreading it evenly.

Step 3: Add the Topping and Bake

  1. Sprinkle the remaining oat mixture evenly over the lemon filling, creating a crumbly topping.
  2. Bake for 20-25 minutes or until the edges are lightly golden and the center is set.

Step 4: Cool, Chill, and Serve

  1. Let the bars cool completely at room temperature, then refrigerate for at least 2 hours before slicing into squares.
  2. Serve chilled for the best texture and flavor.

Nutritional Breakdown (Per Serving)

  • Calories: ~290 kcal
  • Carbohydrates: ~42g
  • Protein: ~4g
  • Fat: ~12g
  • Saturated Fat: ~7g
  • Sugar: ~30g
  • Fiber: ~1g
  • Sodium: ~120mg

These Zesty Lemon Oat Bars combine the richness of buttery oats with the vibrant tang of fresh lemon, making them the perfect balance of sweet and citrusy flavors!

The Secret to Perfect Lemon Oat Bars

While this recipe is fairly straightforward, there are a few key techniques that ensure the best results every time.

1. Use Fresh Lemon Juice & Zest

Bottled lemon juice doesn’t compare to the flavor of freshly squeezed lemons. The zest contains essential oils that add depth and brightness to the filling, so don’t skip it!

2. Don’t Overbake the Bars

The filling should set but still have a slight jiggle in the center when you remove them from the oven. Overbaking can cause the lemon layer to become too firm and lose its creamy texture.

3. Let Them Chill Before Slicing

Patience is key! These bars need time to set properly. Refrigerating them for at least 2 hours ensures clean, neat slices and allows the flavors to meld beautifully.

4. Use Old-Fashioned Rolled Oats for the Best Texture

Instant oats won’t provide the same chewiness and structure as old-fashioned rolled oats. The oats create a hearty, crumbly topping and a solid base that holds up to the creamy filling.

Ways to Customize This Recipe

While these Zesty Lemon Oat Bars are fantastic as-is, you can easily switch things up based on your preferences.

1. Make It More Decadent

  • Drizzle with white chocolate for a rich, creamy contrast to the tart lemon.
  • Dust with powdered sugar just before serving for a bakery-style finish.

2. Add a Nutty Crunch

  • Mix in chopped almonds, pecans, or walnuts into the oat crust and topping for added texture.

3. Try a Different Citrus Flavor

  • Swap out lemon juice for lime juice for a tropical twist.
  • Use a mix of lemon and orange zest to create a unique citrus flavor.

4. Make It Gluten-Free

  • Use a 1:1 gluten-free flour blend in place of all-purpose flour.
  • Ensure you’re using certified gluten-free oats to make this dessert safe for those with gluten sensitivities.

How to Store and Serve These Bars

One of the best things about these lemon oat bars is that they store beautifully and taste even better the next day.

How to Store

  • Refrigerate: Store in an airtight container in the fridge for up to 5 days.
  • Freeze: Wrap individual bars tightly in plastic wrap and freeze for up to 2 months. Thaw in the fridge before serving.

Best Way to Serve

  • Serve chilled for a firmer texture or at room temperature for a softer bite.
  • Enjoy with a hot cup of tea, coffee, or a glass of iced lemonade.
  • Garnish with extra lemon zest or a sprinkle of sea salt for an added touch of brightness.

Frequently Asked Questions (FAQs)

1. Can I use store-bought lemon juice instead of fresh?

While store-bought lemon juice will work, fresh lemon juice is highly recommended for the best flavor. The zest also adds an essential brightness that bottled juice lacks.

2. Can I make these bars dairy-free?

Yes! You can substitute the sweetened condensed milk with a dairy-free version, available in many grocery stores. Also, use vegan butter or coconut oil instead of regular butter.

3. How do I know when the bars are done baking?

The bars are ready when the edges are lightly golden and the center is set but still slightly soft. It will firm up as it cools.

4. Can I double the recipe?

Absolutely! Just use a 9×13-inch baking pan and adjust the baking time accordingly (add about 5-7 more minutes).

5. Why is my crust too crumbly?

Make sure you press the oat mixture firmly into the pan before baking. If it’s too dry, you may need to add an extra tablespoon of melted butter to help it bind.

6. Can I add a meringue topping?

Yes! If you want to make these bars extra special, you can add a whipped meringue topping and lightly toast it with a kitchen torch.

Conclusion: The Perfect Anytime Dessert

These Zesty Lemon Oat Bars are the ideal treat for anyone who loves a combination of citrusy brightness and buttery, oat-filled goodness. They’re simple to make, bursting with fresh lemon flavor, and have a delightful contrast of textures that make every bite a joy.

Whether you’re reminiscing about childhood lemon desserts or discovering a new favorite, these bars are a must-try recipe. Their sweet yet tangy filling and hearty oat crust make them perfect for any occasion—be it a casual afternoon snack, a picnic dessert, or an elegant addition to a dessert table.


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So the next time you’re craving something refreshing, grab some lemons and give these bars a try. You might just find yourself making them again and again!

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Lemon Crumb Bars with a Buttery Streusel Topping


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  • Author: Merry
  • Total Time: 2 hours 50 minutes (including chilling)
  • Yield: 12-16 bars

Description

These Zesty Lemon Oat Bars bring together the perfect balance of bright citrus flavor and hearty oats. A buttery, crumbly oat crust and topping sandwich a creamy, tangy lemon filling, creating a dessert that is both refreshing and satisfying. Perfect for brunch, picnics, or an afternoon treat, these bars are simple to make and bursting with fresh lemon goodness!


Ingredients

For the Oat Crust & Topping:

  • 1 ¼ cups all-purpose flour
  • 1 ¼ cups old-fashioned rolled oats
  • ½ teaspoon salt
  • ½ teaspoon baking soda
  • ½ cup granulated sugar
  • ½ cup packed light brown sugar
  • ¾ cup unsalted butter, melted
  • 1 teaspoon vanilla extract

For the Lemon Filling:

  • 1 (14 oz) can sweetened condensed milk
  • 2 tablespoons finely grated lemon zest
  • ½ cup fresh lemon juice
  • 2 large egg yolks

Instructions

    • Preheat and Prepare the Pan: Preheat the oven to 350°F (175°C). Line an 8×8-inch baking pan with parchment paper.
    • Make the Oat Crust: In a large mixing bowl, combine flour, oats, salt, baking soda, granulated sugar, and brown sugar. Stir in the melted butter and vanilla extract until a crumbly dough forms.
    • Form the Base: Press two-thirds of the oat mixture evenly into the bottom of the prepared pan. Bake for 12-15 minutes until lightly golden.
    • Prepare the Lemon Filling: In a separate bowl, whisk together sweetened condensed milk, lemon zest, lemon juice, and egg yolks until smooth.
    • Layer the Bars: Pour the lemon filling over the baked crust, spreading it evenly. Sprinkle the remaining oat mixture over the top.
    • Bake: Return to the oven and bake for 20-25 minutes, or until the edges are golden and the filling is set.
    • Cool and Chill: Let the bars cool completely, then refrigerate for at least 2 hours before slicing into squares.
    • Serve and Enjoy: Enjoy chilled for the best texture and flavor.

Notes

    • Fresh lemon juice and zest provide the best flavor—avoid bottled juice for optimal taste.
    • For cleaner slices, refrigerate the bars before cutting.
    • Store in an airtight container in the fridge for up to 5 days or freeze for up to 2 months.

  • Prep Time: 15 minutes
  • Cook Time: 35 minutes
  • Category: Dessert
  • Method: Baking
  • Cuisine: American

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