Name: Blueberry Lemon Bars
Prep time: 15 min
Cook time: 30 min
Total time: 43 min
Ingredients: 2 ½ cup blueberries (fresh or frozen); ¼ - ⅓ cup sugar (more if super tart berries); juice of half a lemon; 2 tsp lemon zest (approx. 1½ Tbsp); 2 tsp cornstarch; 1 ½ cup quick oats; 1 ½ cup flour; 1 cup light brown sugar (loosely packed); ½ tsp baking powder; ½ tsp salt; 1 cup unsalted butter (melted and slightly cooled); 2-3 tsp lemon zest; 1 tsp vanilla extract

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These easy blueberry lemon bars are a refreshing treat you are going to love. Simple to prep with a buttery lemon oat layer that is pressed into the bottom and then topped with a lemon blueberry layer with the remaining oat layer crumbled over top for a perfect berry citrus treat. Less than 15 minutes to prep, freezer friendly and since they have fruit and oats, they can be breakfast or dessert, right?!

Blueberry lemon bars stacked on parchment with berries surrounding.

Why We Love These Blueberry Lemon Bars
Ingredient Notes
Ways To Vary This Recipe
Step-By-Step Instructions
Recipe Tips
Storage
More Berry Recipes
Blueberry Lemon Bars Recipe
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These amazing blueberry lemon crumb bars are a twist on my FAVORITE Mixed Berry Crumble Bars, but honestly I may love this version even more!

Fresh, bright and citrusy, these are the perfect spring or summer dessert. And since you can use frozen blueberries, they can technically be made year round!

Love berry dessert recipes? Try these other favorites: No-Bake Lemon Blueberry Cheesecake, Blueberry Lemon Dump Cake, Strawberry Crumble, Blueberry Cheesecake Dip, or find more of The Best Berry Recipes here!

Why We Love These Blueberry Lemon Bars

Blueberry lemon flavor is probably one of my all time favorites. This Blueberry Lemon Coffee Cake, Blueberry Lemon Mug Cake, Blueberry Lemon Overnight Oats are just a few of my faves!

However, these lemony oat bars with all the blueberries may be hands down my all time favorite!

These blueberry lemon bars are:

super simple to make
are so refreshing
easily made gluten-free, dairy free, etc.
freezer friendly
super buttery, crumbly and can be eaten with a fork or handheld–you decide

Can’t wait to hear what you think of these recipe!

Ingredient Notes

See full list of ingredients with exact measurements in recipe card.

Blueberries, quick oats, sugars, lemon and other ingredients labeled on surface.

oats: quick oats are ideal for this recipe as they are smaller and broken down a bit. It allows the bars to hold together so much better. I have made these blueberry lemon oat bars with rolled oats and they will still work for sure, I just find the quick oats to have a nicer bar form.
flour: all purpose flour for best results. You can use an all purpose 1:1 gluten free baking flour if desired!
brown sugar: light brown sugar is what we use.I don’t recommend dark brown sugar in this recipe as the extra molasses flavor won’t be ideal with the lemon flavor and could overshadow it.
butter: unsalted butter, melted and slightly cooled. You can use salted butter and just half the amount of salt.
blueberries: Fresh or frozen berries will work in this recipe. If you use frozen, there is no need to thaw them before using. Taste the berries to determine if they are super tart–you can add more sugar if they seem a bit sour or tart.
lemon: fresh lemon juice and lemon zest is a must for the best lemon flavor in these blueberry bars. There really is no substitute!
corn starch: This will allow the berry mixture to thicken a bit so that they don’t become watery when baking. You could use a bit of flour or arrowroot powder if you don’t have any.

Ways To Vary This Recipe

change up the berries: you can use any berries really when making this, or make a mixed berry variation as we love in these Mixed Berry Crumble Bars. Strawberries, raspberries, blackberries–any will work!
add an icing drizzle: you can drizzle a nice icing glaze over top of these lemon blueberry bars after they have cooled a bit. The glaze in this Blueberry Lemon Coffee Cake should work well!
make it vegan and/or gluten free: for vegan, use a plant based butter in place of the real butter. There are no eggs in this recipe so you don’t have to worry about that either! For a gluten-free version, use a 1:1 all purpose gluten-free flour and make sure your oats say certified gluten-free!

Step-By-Step Instructions

Step 1: Preheat oven to 350°F. In a medium bowl, mix together sugar, lemon juice, lemon zest, berries and corn starch. Set aside.

Whisked oats, brown sugar, flour and other ingredients in bowl with whisk.

Step 2: In a separate bowl, combine oats, flour, brown sugar, sea salt, and baking powder and whisk together.

Butter and lemon zest added to oat mixture.

Step 3: Add in melted butter, lemon zest and vanilla and stir to combine.

Step 4: Mixture will be somewhat crumbly, and that is fine!

Lemon oat bar mixture pressed into lined pan.

Step 5: In an 8×8 in. pan, lined with parchment, press 2/3 of the oat mixture firmly into the pan (its roughly 2-2 ½ cups mixture).

Blueberry lemon mixture added to pan with oat layer.

Step 6: Add the blueberry mixture on top to cover evenly and spread into as even of a layer as you can.

Lemon oat crumble sprinkled over berries.

Step 7: Place in the oven and bake for 30-35 minutes or until berries are bubbling and oats on the top are golden brown.

Step 8: Allow to cool completely before cutting—best to refrigerate to set for easier eating if wanting handheld. If wanting to eat with spoon or fork, you can eat warm, just too messy to make handheld!

Recipe Tips

Adjust the berry sweetness as desired. If your berries are a bit tart, you may want to adjust the amount of sugar. If it’s peak berry season and they are nice and sweet, you may want to half the amount of sugar. Up to you!

For easier and cleaner cut bars, refrigerate these blueberry lemon oat bars for several hours before cutting. This makes for much less of a mess! Run the knife under hot water before slicing and then wipe clean between each cut and rinse again.

If you aren’t planning to eat them as bars, no need to refrigerate to set. These can be eaten with a fork for sure and if you are not concerned about them holding together well, then for sure, dig in whenever you are ready!

Storage

These lemon blueberry bars will keep in the refrigerator for up to one week in an airtight container. Allow them to sit out for about 15 minutes before serving to allow them to come to room temperature or warm them up in the microwave.

To freeze, allow the bars to cool completely. Slice them and wrap individually or place in an airtight freezer safe container and freeze for up to 3 months.