Lemon Oatmeal Crumble Bars – Zesty, Sweet, and Perfectly Chewy

🎉 Introduction

If you love the refreshing zing of lemon desserts and the comfort of buttery crumble toppings, you’re going to fall head over heels for these Lemon Oatmeal Crumble Bars. With a tangy, lemony filling nestled between two layers of a golden, oat-infused crumb crust, they strike the perfect balance of sweet and tart.

Whether you’re planning a bake sale, brunch spread, or just want a dessert that’s both rustic and elegant, these bars will never disappoint. Best part? They’re made with simple pantry staples and require no mixer!

🧰 Equipment Needed

• 8×8 or 9×9-inch square baking dish
• Mixing bowls
• Whisk
• Measuring cups and spoons
• Zester or fine grater
• Oven
• Rubber spatula or spoon
• Parchment paper (optional, for easy removal)

🛒 Ingredients

🍋 Lemon Filling

• 1 (14 oz) can sweetened condensed milk
• 1/2 cup lemon juice (freshly squeezed preferred)
• 2 tsp lemon zest
• 1 egg yolk (optional, for extra richness)
• 1/2 tsp vanilla extract

🥣 Crumble & Base

• 1 cup all-purpose flour
• 1 cup old-fashioned rolled oats
• 2/3 cup brown sugar (light or dark)
• 1/2 tsp baking soda
• 1/4 tsp salt
• 1/2 tsp cinnamon (optional, adds warmth)
• 3/4 cup unsalted butter, melted and slightly cooled

👩‍🍳 Directions

Step 1: Preheat Oven

• Preheat your oven to 350°F (175°C).
• Line your baking dish with parchment paper or lightly grease it.

Step 2: Mix the Crumble Base

• In a large bowl, combine:
  • 1 cup flour
  • 1 cup oats
  • 2/3 cup brown sugar
  • 1/2 tsp baking soda
  • 1/4 tsp salt
  • Optional: 1/2 tsp cinnamon
• Pour in the melted butter and stir until mixture resembles coarse crumbs.

Step 3: Press & Pre-Bake the Base

• Press 2/3 of the oat mixture into the bottom of your prepared baking pan.
• Bake for 10–12 minutes, or until lightly golden.

Step 4: Make the Lemon Layer

• In a medium bowl, whisk together:
  • 1 can sweetened condensed milk
  • 1/2 cup lemon juice
  • 2 tsp lemon zest
  • 1/2 tsp vanilla
  • Optional: 1 egg yolk for a richer texture
• Pour over the slightly cooled crust and spread evenly.

Step 5: Add the Crumble Topping

• Sprinkle the remaining oat mixture evenly over the lemon layer.
• Press lightly so it adheres but remains crumbly.

Step 6: Bake Again

• Bake for 20–25 minutes, or until the top is golden brown and the lemon filling has set.

Step 7: Cool & Slice

• Let the bars cool at room temperature for 1 hour, then refrigerate for another hour to fully set before slicing.

🍽️ Servings & Timing

• Servings: 9–12 bars
• Prep Time: 15 minutes
• Cook Time: 35 minutes
• Cooling Time: 1–2 hours
• Total Time: ~2 hours 15 minutes

🧊 Storage & Reheating

Storage:

• Store bars in an airtight container in the refrigerator for up to 5 days.

Freezing:

• Wrap each bar in plastic wrap and freeze in a container for up to 2 months.

Reheating (optional):

• Let thaw at room temperature, or warm slightly in a low oven (300°F for 5–7 min) for a just-baked feel.

🥄 Variations

• Gluten-Free: Use a gluten-free 1:1 baking flour and certified gluten-free oats.
• Coconut Lemon Bars: Add 1/2 cup shredded coconut to the crust for a tropical twist.
• Berry Burst: Mix 1/2 cup fresh blueberries or raspberries into the lemon filling.
• Graham Base Swap: Replace 1/3 of the oats with crushed graham crackers for a firmer texture.
• Maple or Honey: Substitute half of the brown sugar with maple syrup or honey for a deeper flavor.

❓ 10 FAQs

1. Can I use bottled lemon juice?
Yes, but fresh juice will give a brighter, more authentic flavor.

2. Can I skip the egg yolk?
Yes! It’s optional for a richer custard feel but not necessary.

3. Why is my crust crumbly?
Make sure the butter is fully mixed in — it should resemble wet sand.

4. Can I double the recipe?
Absolutely. Use a 9×13-inch pan and adjust the bake time by 5–10 minutes.

5. Is condensed milk the same as evaporated milk?
No — use only sweetened condensed milk for this recipe.

6. Can I make these vegan?
Use vegan butter, plant-based condensed milk, and omit the egg yolk.

7. What kind of oats should I use?
Old-fashioned rolled oats are best for texture. Avoid quick oats.

8. How do I get clean cuts?
Chill well before slicing and use a sharp knife wiped clean between cuts.

9. Can I add nuts?
Yes! Chopped walnuts or pecans in the crumble topping are delicious.

10. Can I make this without a mixer?
Absolutely — just a whisk and spoon will do!

🏁 Conclusion

These Lemon Oatmeal Crumble Bars are the epitome of simple luxury. With a chewy oat base, tangy citrus filling, and buttery golden crumble, each bite is a harmony of flavor and texture. Whether you’re serving them at a garden party, tucking them into lunchboxes, or enjoying them with tea, they’ll be a sunny addition to any day.

Easy to bake, even easier to love — this recipe might just become your new go-to.

Adam

Lemon Oatmeal Crumble Bars – Zesty, Sweet, and Perfectly Chewy

If you love the refreshing zing of lemon desserts and the comfort of buttery crumble toppings, you’re going to fall head over heels for these Lemon Oatmeal Crumble Bars. With a tangy, lemony filling nestled between two layers of a golden, oat-infused crumb crust, they strike the perfect balance of sweet and tart. Whether you’re planning a bake sale, brunch spread, or just want a dessert that’s both rustic and elegant, these bars will never disappoint. Best part? They’re made with simple pantry staples and require no mixer!

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 35 minutes mins

cooling time 2 hours hrs

Total Time 2 hours hrs 50 minutes mins

Servings: 12 bars

Ingredients Equipment Method Notes

Ingredients

  

🍋 Lemon Filling

• 1 14 oz can sweetened condensed milk
• 1/2 cup lemon juice freshly squeezed preferred
• 2 tsp lemon zest
• 1 egg yolk optional, for extra richness
• 1/2 tsp vanilla extract

🥣 Crumble & Base

• 1 cup all-purpose flour
• 1 cup old-fashioned rolled oats
• 2/3 cup brown sugar light or dark
• 1/2 tsp baking soda
• 1/4 tsp salt
• 1/2 tsp cinnamon optional, adds warmth
• 3/4 cup unsalted butter melted and slightly cooled

Equipment

• 8×8 or 9×9-inch square baking dish
• Mixing bowls
• Whisk
• Measuring cups and spoons
• Zester or fine grater
• Oven
• Rubber spatula or spoon
• Parchment paper (optional, for easy removal)

Method

 

Step 1: Preheat Oven

1. Preheat your oven to 350°F (175°C).
2. Line your baking dish with parchment paper or lightly grease it.

Step 2: Mix the Crumble Base

1. In a large bowl, combine:
2. 1 cup flour
3. 1 cup oats
4. 2/3 cup brown sugar
5. 1/2 tsp baking soda
6. 1/4 tsp salt
7. Optional: 1/2 tsp cinnamon
8. Pour in the melted butter and stir until mixture resembles coarse crumbs.

Step 3: Press & Pre-Bake the Base

1. Press 2/3 of the oat mixture into the bottom of your prepared baking pan.
2. Bake for 10–12 minutes, or until lightly golden.

Step 4: Make the Lemon Layer

1. In a medium bowl, whisk together:
2. 1 can sweetened condensed milk
3. 1/2 cup lemon juice
4. 2 tsp lemon zest
5. 1/2 tsp vanilla
6. Optional: 1 egg yolk for a richer texture
7. Pour over the slightly cooled crust and spread evenly.

Step 5: Add the Crumble Topping

1. Sprinkle the remaining oat mixture evenly over the lemon layer.
2. Press lightly so it adheres but remains crumbly.

Step 6: Bake Again

1. Bake for 20–25 minutes, or until the top is golden brown and the lemon filling has set.

Step 7: Cool & Slice

1. Let the bars cool at room temperature for 1 hour, then refrigerate for another hour to fully set before slicing.

Notes

🧊 Storage & Reheating
Storage:

Store bars in an airtight container in the refrigerator for up to 5 days.

Freezing:

Wrap each bar in plastic wrap and freeze in a container for up to 2 months.

Reheating (optional):

Let thaw at room temperature, or warm slightly in a low oven (300°F for 5–7 min) for a just-baked feel.

🥄 Variations
Gluten-Free: Use a gluten-free 1:1 baking flour and certified gluten-free oats.

Coconut Lemon Bars: Add 1/2 cup shredded coconut to the crust for a tropical twist.

Berry Burst: Mix 1/2 cup fresh blueberries or raspberries into the lemon filling.

Graham Base Swap: Replace 1/3 of the oats with crushed graham crackers for a firmer texture.

Maple or Honey: Substitute half of the brown sugar with maple syrup or honey for a deeper flavor.

❓ 10 FAQs
1. Can I use bottled lemon juice?
Yes, but fresh juice will give a brighter, more authentic flavor.

2. Can I skip the egg yolk?
Yes! It’s optional for a richer custard feel but not necessary.

3. Why is my crust crumbly?
Make sure the butter is fully mixed in — it should resemble wet sand.

4. Can I double the recipe?
Absolutely. Use a 9×13-inch pan and adjust the bake time by 5–10 minutes.

5. Is condensed milk the same as evaporated milk?
No — use only sweetened condensed milk for this recipe.

6. Can I make these vegan?
Use vegan butter, plant-based condensed milk, and omit the egg yolk.

7. What kind of oats should I use?
Old-fashioned rolled oats are best for texture. Avoid quick oats.

8. How do I get clean cuts?
Chill well before slicing and use a sharp knife wiped clean between cuts.

9. Can I add nuts?
Yes! Chopped walnuts or pecans in the crumble topping are delicious.

10. Can I make this without a mixer?
Absolutely — just a whisk and spoon will do!

🏁 Conclusion
These Lemon Oatmeal Crumble Bars are the epitome of simple luxury. With a chewy oat base, tangy citrus filling, and buttery golden crumble, each bite is a harmony of flavor and texture. Whether you’re serving them at a garden party, tucking them into lunchboxes, or enjoying them with tea, they’ll be a sunny addition to any day.

Easy to bake, even easier to love — this recipe might just become your new go-to.