Lemon Oatmeal Crumble Bars

These Lemon Oatmeal Crumble Bars are a perfect combination of tangy lemon filling, buttery oatmeal crust, and a generous crumble topping. With their zesty flavor and delightful texture, these bars are perfect for any occasion, whether it’s a casual gathering or a special treat.

Why You’ll Love This Recipe

I love how these Lemon Oatmeal Crumble Bars balance a buttery, slightly sweet oat crust with a rich, citrusy lemon filling. The crumble topping adds the perfect crunch, while the creamy lemon layer gives a tangy burst of flavor. It’s such a satisfying dessert that’s both sweet and refreshing. The best part? It’s super easy to make and comes together in just a little over an hour. Whether I’m craving a citrus dessert or looking to impress at a gathering, these bars are always a hit!

Ingredients

For the Crust & Topping:

• 7 tablespoons (99g) unsalted butter, softened to room temperature

• 3/4 cup (150g) light or dark brown sugar, packed

• 1 teaspoon vanilla extract

• 1 cup (125g) all-purpose flour (spooned & leveled)

• 1 teaspoon baking powder

• 1/4 teaspoon salt

• 1 cup (85g) old-fashioned oats or quick oats (not instant)

For the Lemon Filling:

• 1 can (14 ounces) full-fat sweetened condensed milk

• 6 tablespoons (90ml) lemon juice (from about 2 lemons)

• 1 tablespoon lemon zest (from about 1 lemon)

(Hint: Check out the full list of ingredients and measurements in the recipe card below.)

Directions

1. Prepare the oven and pan: Preheat the oven to 350°F (177°C). Line an 8-inch square baking pan with parchment paper for easy removal of the bars.

2. Make the crust and topping: Using a handheld or stand mixer, beat the softened butter and brown sugar on medium-high speed until fully combined (about 1 minute). Scrape down the sides of the bowl and add the vanilla extract. Beat again on medium-high for 30 seconds until incorporated. Add the flour, baking powder, salt, and oats. Mix on medium speed until combined. The mixture should be crumbly and dry, forming between 3–3.5 cups of mixture in total.

3. Form the crust: Press slightly more than half of the crumble mixture into the bottom of the prepared pan to form the crust. You want slightly more for the crust than for the topping.

4. Bake the crust: Bake for 12 minutes, then remove from the oven.

5. Make the lemon filling: In a medium bowl, whisk together the sweetened condensed milk, lemon juice, and lemon zest until smooth and thick.

6. Assemble the bars: Pour the lemon filling over the pre-baked crust while it’s still hot and spread it evenly. Sprinkle the remaining crumble mixture on top of the lemon filling.

7. Bake again: Return the bars to the oven and bake for an additional 22–25 minutes, or until the edges are lightly golden and the center is set. Be careful not to over-bake.

8. Cool and cut: Once done, remove from the oven and let the pan cool completely on a wire rack. Once cooled, use the parchment paper to lift the bars out of the pan and slice into squares.

Servings and Timing

• Servings: This recipe yields 16 bars.

• Prep Time: 15 minutes

• Cook Time: 38 minutes

• Total Time: 53 minutes

Variations

• Add-Ins: I sometimes add a handful of chopped nuts, like almonds or walnuts, to the crumble mixture for extra crunch and flavor.

• Berry Twist: You can add fresh berries, such as blueberries or raspberries, to the lemon filling for a burst of extra fruitiness.

• Double the Recipe: If I’m hosting a large crowd, I like to double the recipe. I simply double all the ingredients and bake it in a 9×13-inch pan. Just remember to adjust the baking time slightly!

Storage/Reheating

• Storage: I store any leftover bars at room temperature for up to 2 days or refrigerate them for up to 1 week.

• Freezing: To freeze, I place the cut bars in a single layer, separated by parchment paper, in a freezer-safe container. They’ll keep for up to 3 months. To enjoy, I thaw them overnight in the refrigerator and bring them to room temperature before serving.

FAQs

1. Can I use a different type of milk for the filling?

I recommend using full-fat sweetened condensed milk, as it’s essential for the filling to set properly. Using fat-free versions will not work.

2. Can I make these bars gluten-free?

Yes, you can substitute the all-purpose flour with a gluten-free flour blend. Just make sure the oats are certified gluten-free.

3. How can I make the crust and topping more flavorful?

I sometimes add a pinch of cinnamon or nutmeg to the crumble mixture for extra warmth and spice.

4. Can I use a different citrus for the filling?

While lemon is traditional, you can experiment with lime or orange juice and zest for a different flavor profile.

5. How should I cut the bars?

Once cooled, I use a sharp knife to cut the bars into squares. Make sure to let them cool completely to prevent them from falling apart.

Conclusion

These Lemon Oatmeal Crumble Bars are the perfect treat if you’re craving something tangy, sweet, and satisfying. The buttery crust, zesty lemon filling, and crunchy topping make for a delightful combination that’s hard to resist. They’re easy to make, and they’re always a crowd-pleaser. Whether you’re serving them at a gathering or enjoying them on your own, these bars are sure to brighten your day!