These Lemon Oatmeal Crumble Bars are sunshine in dessert form—bright, tangy, and beautifully balanced with a rich, buttery oat crust. With layers of creamy lemon filling and golden crumble, they’re the perfect treat for spring brunches, afternoon coffee breaks, or anytime you need a pick-me-up.
Simple to make and even easier to devour, this recipe delivers big flavor with wholesome ingredients you already have in your pantry.
Why You’ll Love Lemon Oatmeal Crumble Bars
Zesty & Sweet: The perfect blend of tart lemon and sweet oat crumble.
Textural Delight: Creamy filling, crunchy topping—every bite is a treat.
Make-Ahead Friendly: Stores well for days or can be frozen for future cravings.
Crowd-Pleasing: Great for potlucks, picnics, and dessert tables.
Easy to Customize: Try it with lime, orange, or even berry fillings!
Time Needed
Prep Time: 15 minutes
Cook Time: 38 minutes
Total Time: 53 minutes
Servings: 16 bars
Ingredients
For the Crust & Topping
7 tablespoons (99g) unsalted butter, softened
3/4 cup (150g) packed light or dark brown sugar
1 teaspoon vanilla extract
1 cup (125g) all-purpose flour
1 teaspoon baking powder
1/4 teaspoon salt
1 cup (85g) old-fashioned or quick oats (not instant)
For the Lemon Filling
1 can (14 oz) full-fat sweetened condensed milk
6 tablespoons (90ml) fresh lemon juice (about 2 lemons)
1 tablespoon lemon zest (about 1 lemon)
How to Make Lemon Oatmeal Crumble Bars
1️⃣ Prep the Pan
Preheat oven to 350°F (177°C). Line an 8-inch square baking pan with parchment paper.
2️⃣ Make the Crust & Topping
Beat butter and brown sugar until creamy (about 1 minute). Add vanilla and mix again.
Stir in flour, baking powder, salt, and oats until mixture is crumbly. You’ll have about 3 to 3.5 cups of mixture.
3️⃣ Press and Bake the Crust
Use slightly more than half of the mixture to press into the bottom of the pan.
Bake for 12 minutes, then remove from the oven.
4️⃣ Whip Up the Lemon Filling
Whisk together sweetened condensed milk, lemon juice, and zest until thick and smooth.
5️⃣ Assemble and Bake Again
Pour lemon filling over the hot crust, spreading evenly. Sprinkle remaining crumble on top.
Bake for 22–25 more minutes, until edges are golden and center is set.
6️⃣ Cool and Slice
Cool completely on a wire rack, then lift out and slice into squares.
Storage Tips
Room Temp: Store for up to 2 days in an airtight container.
Fridge: Keeps fresh for up to 1 week.
Freezer: Freeze in layers separated by parchment for up to 3 months. Thaw overnight in the fridge before serving.
Frequently Asked Questions
1. Can I use bottled lemon juice?
Fresh juice is best, but bottled works in a pinch.
2. What kind of oats should I use?
Old-fashioned or quick oats—just avoid instant.
3. Can I make these gluten-free?
Yes! Swap in a 1:1 gluten-free flour blend and certified GF oats.
4. Is it okay to double the recipe?
Absolutely. Use a 9×13-inch pan, pre-bake crust for 18 minutes, then bake the filled bars for 35 minutes.
5. How do I make it extra lemony?
Add an extra teaspoon of zest or a drop of lemon extract for a citrus punch.
Final Thoughts
Lemon Oatmeal Crumble Bars are the ultimate fusion of bright, citrusy flavor and comforting, buttery crumble. Whether you’re baking for a gathering or just treating yourself, these bars deliver every time. So go ahead—whip up a batch, share with friends (or not), and savor the sunshine in every bite. 🍋💛
Print
Lemon Oatmeal Crumble Bars
- Total Time: 53 minutes
- Yield: 16 bars 1x
Description
These Lemon Oatmeal Crumble Bars are sunshine in dessert form—bright, tangy, and beautifully balanced with a rich, buttery oat crust. Perfect for brunches or sweet snacking anytime.
Ingredients
- For the Crust & Topping:
- 7 tablespoons (99g) unsalted butter, softened
- 3/4 cup (150g) packed light or dark brown sugar
- 1 teaspoon vanilla extract
- 1 cup (125g) all-purpose flour
- 1 teaspoon baking powder
- 1/4 teaspoon salt
- 1 cup (85g) old-fashioned or quick oats (not instant)
- For the Lemon Filling:
- 1 can (14 oz) full-fat sweetened condensed milk
- 6 tablespoons (90ml) fresh lemon juice (about 2 lemons)
- 1 tablespoon lemon zest (about 1 lemon)
Instructions
- Preheat oven to 350°F (177°C). Line an 8-inch square baking pan with parchment paper.
- Beat butter and brown sugar until creamy (about 1 minute). Add vanilla and mix again.
- Stir in flour, baking powder, salt, and oats until mixture is crumbly.
- Use slightly more than half of the mixture to press into the bottom of the pan. Bake for 12 minutes, then remove from oven.
- Whisk together sweetened condensed milk, lemon juice, and zest until thick and smooth.
- Pour lemon filling over the hot crust, spreading evenly. Sprinkle remaining crumble on top.
- Bake for 22–25 more minutes, until edges are golden and center is set.
- Cool completely on a wire rack, then lift out and slice into squares.
Notes
Store at room temperature for up to 2 days or in the fridge for 1 week. Freeze in layers with parchment for up to 3 months. Add extra zest or a drop of lemon extract for more citrus punch.
- Prep Time: 15 minutes
- Cook Time: 38 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 bar
- Calories: 220
- Sugar: 18g
- Sodium: 85mg
- Fat: 9g
- Saturated Fat: 5g
- Unsaturated Fat: 3g
- Trans Fat: 0g
- Carbohydrates: 32g
- Fiber: 1g
- Protein: 3g
- Cholesterol: 20mg
Keywords: lemon, oatmeal bars, crumble, dessert, easy baking