Hey y’all! If you adore a combo of sweet, tart, and buttery goodness, these Easy Lemon Oatmeal Crumble Bars are about to become your new favorite treat. With a golden, crispy oat crust, an irresistible, zesty lemon filling, and a crumbly topping, these bars bring a little sunshine to any table. Perfect for snacking, potlucks, picnic baskets, or light desserts after dinner—everyone will love them! Let’s get cooking!
Why You'll Love This Easy Lemon Oatmeal Crumble Bars Recipe
- Bursting with fresh lemon flavor for a tangy and refreshing treat.
- Uses pantry staples and comes together in just over 30 minutes.
- Great for making ahead—bars stay fresh and delicious for days.
- No mixer required, just a bowl and spoon—hello, easy cleanup!
- Perfect snack, dessert, or even breakfast with a cup of coffee!
Ingredients for Easy Lemon Oatmeal Crumble Bars
- 1 cup (225g) unsalted butter, melted
- 1 cup (200g) light brown sugar, packed
- ½ cup (100g) granulated sugar
- 2 cups (160g) old-fashioned rolled oats
- 1 ½ cups (190g) all-purpose flour
- ½ teaspoon salt
- 1 teaspoon baking powder
- 2 teaspoons fresh lemon zest (about 2 lemons)
- ¾ cup (180ml) fresh lemon juice (about 3-4 lemons)
- 1 tablespoon cornstarch
- ½ teaspoon vanilla extract
- 2 large eggs
- Powdered sugar, for dusting (optional)
How to Make Easy Lemon Oatmeal Crumble Bars
Step 1: Prep the Pan and Oven
Preheat your oven to 350°F (175°C). Line a 9×13-inch (23x33cm) baking pan with parchment paper, leaving some overhang for easy removal.
Step 2: Make the Oatmeal Crumble
In a large bowl, mix melted butter, brown sugar, and granulated sugar until smooth and combined. Stir in oats, flour, salt, baking powder, and lemon zest until crumbly. Set aside 1 ½ cups of the oat mixture for the topping.
Step 3: Press the Crust
Firmly press the remaining oat mixture into the bottom of the pan to form an even layer for the crust.
Step 4: Prepare the Lemon Layer
In a medium bowl, whisk together the eggs, lemon juice, cornstarch, and vanilla extract until smooth. Pour this zesty filling over the oat crust.
Step 5: Add the Crumble Topping
Evenly sprinkle the reserved oat mixture over the lemon filling for a delicious crumbly topping.
Step 6: Bake and Cool
Bake for 28–32 minutes, or until the top is golden and the lemon filling is just set. Let cool completely in the pan. Once cooled, lift out with parchment and cut into bars. Dust with powdered sugar if desired.
Notes for Baking Easy Lemon Oatmeal Crumble Bars
- Chill the bars before slicing for extra clean edges.
- Use fresh lemon juice for authentic zesty flavor; bottled juice just isn’t the same (tips for juicing lemons).
- Old-fashioned oats add the perfect chewy texture; avoid quick oats for best results.
Easy Lemon Oatmeal Crumble Bars Variations
- Raspberry Lemon: Add ½ cup fresh or frozen raspberries into the lemon layer for an extra burst of flavor.
- Gluten-Free: Substitute the all-purpose flour with your favorite 1:1 gluten-free flour blend.
- Vegan: Use vegan butter and swap eggs for ½ cup unsweetened applesauce.
Equipment Needed for Easy Lemon Oatmeal Crumble Bars
- 9×13-inch (23x33cm) baking pan
- Parchment paper
- Mixing bowls
- Whisk and spatula
- Measuring cups and spoons
How to Store Easy Lemon Oatmeal Crumble Bars
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, wrap tightly and freeze for up to 2 months. Thaw overnight in the fridge before serving.
Serving Suggestions for Easy Lemon Oatmeal Crumble Bars
- Serve chilled or at room temperature with a dusting of powdered sugar.
- Pair with a cup of hot tea, iced coffee, or fresh berries for a lovely treat.
- Top with a scoop of vanilla ice cream for an indulgent dessert!
Pro Tips for the Best Easy Lemon Oatmeal Crumble Bars
- Make sure your lemon juice is freshly squeezed for the best taste (learn more about lemon juice).
- Let bars cool completely in the pan before slicing for the neatest cuts.
- For extra crunch, add ½ cup chopped toasted almonds or pecans to your oat topping.
Easy Lemon Oatmeal Crumble Bars FAQ
- Can I use bottled lemon juice instead of fresh?
- Fresh lemon juice has a brighter, more vibrant flavor, which is key for these bars; bottled juice can taste flat and acidic.
- Can I make these Easy Lemon Oatmeal Crumble Bars ahead of time?
- Absolutely! They keep well in the fridge for up to a week and freeze beautifully for up to 2 months.
- Can I use quick oats?
- Old-fashioned oats yield the best chewy texture—quick oats can make the bars too dense and mushy (learn more about oatmeal types).
Prep time: 15 minutes
Total time: 45 minutes
Yield: 16 bars
Ingredients
- 1 ½ cups old-fashioned rolled oats
- 1 ¼ cups all-purpose flour
- ¾ cup packed light brown sugar
- ½ teaspoon baking powder
- ¼ teaspoon salt
- ¾ cup unsalted butter, melted
- 1 tablespoon lemon zest
- ½ cup lemon juice (about 2 lemons)
- 1 can (14 oz) sweetened condensed milk
Instructions
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1Preheat oven to 350°F (175°C) and line an 8x8 inch baking pan with parchment paper.
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2In a large bowl, combine oats, flour, brown sugar, baking powder, and salt. Stir in melted butter and lemon zest until the mixture forms moist crumbs.
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3Press about two-thirds of the oat mixture evenly into the bottom of the prepared pan to form the crust.
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4In a separate bowl, whisk together lemon juice and sweetened condensed milk until smooth. Pour lemon mixture evenly over the crust.
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5Sprinkle the remaining oat crumble evenly over the lemon layer.
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6Bake for 28–32 minutes, or until the top is golden. Allow bars to cool completely before cutting into squares.
Approximate Information for One Serving
Nutrition Disclaimers
Number of total servings shown is approximate. Actual number of servings will depend on your preferred portion sizes.
Nutritional values shown are general guidelines and reflect information for 1 serving using the ingredients listed, not including any optional ingredients. Actual macros may vary slightly depending on specific brands and types of ingredients used.
To determine the weight of one serving, prepare the recipe as instructed. Weigh the finished recipe, then divide the weight of the finished recipe (not including the weight of the container the food is in) by the desired number of servings. Result will be the weight of one serving.
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