You can make these delicious blueberry oatmeal bars with only 7 simple ingredients! It takes less than an hour from preparing to baking these bars. I use the same dough for the crust and crumbles which makes this recipe extra easy!
If you enjoyed my peach bars and strawberry crumble bars, I believe you’ll enjoy today’s summer bar recipe which is as delicious and easy as my other fruit bars.
Crunchy crumbles and lemony blueberry filling are delicious together in these oatmeal blueberry bars. It’s like eating blueberry jam between the crust and the crumbles.
They are perfect for dessert or a snack. These blueberry lemon bars can be a special breakfast treat as well.
This dessert is pretty easy to make. Let’s start with the ingredients and continue with step by step photos.
Ingredients you’ll need
- Blueberries-I use lots of blueberries to completely cover the crust.
- Lemon-I use both the juice and zest for the filling.
- Cornstarch-It thickens the filling.
- All-purpose flour-It creates structure in the crust and crumbles.
- Oatmeal-I use rolled oats almost the same amount of flour.
- Butter-I use melted butter, it brings the dough together besides its delicious taste.
- Sugar-I use granulated sugar both for the dough and the filling.
Step by step instructions
First I place the flour, oatmeal, sugar into a medium bowl and mix with a spoon.
Then I add the melted butter on top and stir with a spoon.
I set aside ⅓ of the mixture (it is just a little more than packed ⅔ cup or to be precise it is 190 grams) and place ⅔ of the mixture into an ovenproof dish that is lined with parchment paper and spread the mixture evenly with a spoon. If you like, you can use your hands to spread.
Next, I place the blueberries into a medium bowl and mix in the sugar, cornstarch, lemon juice and lemon zest.
Then I place the blueberry mixture over the crust and spread ⅓ of the dough mixture that I set aside on top. I slightly press to the crumbles with my fingertips so they can stick to blueberries.
Finally, I bake for almost 38-40 minutes or until the top is golden brown and the crumbles are crunchy.
I let it completely cool before I cut it into 16 slices. They are delicious when they are warm but it is like eating blueberry oatmeal crumble instead of eating blueberry bars.
I hope you enjoy these blueberry lemon bars!
Frequently asked questions
Yes, you can! You don’t need to thaw before using.
You can store totally cooled bars in an airtight container for up to a week. Don’t store at room temperature as they’ll become soft.
You can freeze totally cooled bars for up to 3 months in an airtight container and thaw overnight in the fridge.
MY OTHER SUMMER RECIPES!
- Frozen Strawberry White Chocolate Cups
- No-Churn Praline Ice Cream
- Kiwi Orange Popsicles
- Healthy Lemonade
- Frozen Banana Bites
- Frozen Chocolate Banana Bites
I love hearing from you! If you try this recipe or my other recipes please leave a comment and give a star rating!
Blueberry Oatmeal Bars
Ingredients
Crust and Cumbles
- 140 grams (1 cup) all-purpose flour, dip and sweep
- 144 grams (1 and ½ cup) rolled oats
- 140 grams (⅔ cup) granulated sugar
- 150 grams (⅔ cup) unsalted butter, melted and cooled*
Blueberry Filling
- 300 grams (2 cups) blueberries**
- 50 grams (¼ cup) granulated sugar
- 2 teaspoons cornstarch
- 1 tablespoon lemon juice
- 1 and ½ teaspoons lemon zest (zest of 1 large lemon)
Instructions
- Preheat the oven to 350°F(177°C). Grease 8 inch (20cm) square ovenproof dish and line the bottom and sides with parchment paper, about 2 inches(5 cm) of overhang on each side.
- Place the flour, rolled oats, sugar in a medium bowl and stir with a spoon/spatula. Stir in the melted butter.
- Set ⅓ of the mixture aside(it is 190 grams or just alittle more than a fully packed ⅔ cup) for the crumbles. Using a spoon spread remaning ⅔ of the mixture into an oven-proof dish that is lined with parchment paper.
- Place the blueberries into a medium bowl. Mix in the sugar, cornstarch, lemon juice and lemon zest.
- Pour the blueberry mixture over the crust and then sprinkle the remaining dough over the blueberries. Gently press to the crumbles with your fingertips so they will stick to the blueberries.
- Bake for almost 38-40 minutes until the top becomes golden brown and the crumbles are crunchy. Let it cool completely before cutting into slices.
Ada-Lou
I am on a low histamine diet. So substituted coconut oil for butter, oatmeal flour for all purpose flour, added chopped up brazil nuts, cocnut sugar for white sugar, blueberries did not need sugar, just added tapioca flour (instead of cornstarch). The end result was AMAZING!!
Meymi
Hi Ada-Lou, Thank you so much for your detailed feedback!
Anne
Absolutely loved your Blueberry Oatmeal Bars! Didn’t make any changes to the recipe. Served them with vanilla ice cream and a dollop of whipped cream this afternoon. All my friends just raved about them. Your recipe is a real keeper
Meymi
Hi Anne, I’m so happy to hear both you and your friends enjoyed this recipe so much! Thank you for your comment!
Becky
I followed this recipe exactly and the results were so good! The blueberries were sweet and a little gooey, much better than any store bought version. I will be making this again and can’t wait to try it with other fruits too. Thanks for the recipe!
Meymi
Hi Becky, I’m so glad you enjoyed this recipe so much! Thank you for your comment!
Isabella
Really nice I was a bit hesitant adding all the cornstarch and sugar as i am looking for a healthy tasty breakfast option. But this was great i didn’t have a punnet of blueberries so i used a frozen mix berries mix, and it tasted fab! Saving this recipe!
Amy
These ere an absolute hit! They were gone in 10 minutes! I will definitely make them again…and again!
Meymi
Hi Amy, I’m so glad you loved these bars so much. Thank you for your comment!
Carol
Absolutely love these bars, way better than pie! I add an extra cup of blueberries.
Meymi
Hi Carol, I’m so happy to hear you that love these bars so much! Thank you for your feedback!
PT Diaz
Made this for Christmas morning breakfast. Family enjoyed the chewiness of the rolled oats and the sweetness of blueberries. This was a nice compliment to the spinach quiche we ate. Will make it again!
Meymi
I’m so happy to hear that your family enjoyed this recipe. Thank you for your comment!
Cindy
I love these. Easy to make and I really like weighing the ingredients. Added a cream cheese/ egg mixture to the bottom crust before adding the blueberry mixture. Had to bake them longer. Took them to another level. Received many compliments. Thank you for sharing your creativity. Delicious!!
Meymi
Thank you so much for your feedback, Cindy! The addition of cream cheese mixture sounds delicious!
Alexia
I don’t normally leave reviews, but I had to share that this dessert was AMAZING. My daughter and I made these bars for our dinner guests – they were a huge hit! We needed it to be dairy free for our guests, so we substituted melted coconut oil for the butter. We also only used 1/3 cup of honey instead of sugar for the crust, and only used frozen blueberries and a drizzle of honey for the filling (no sugar or cornstarch, and I was out of lemon). My family requested I make it again tomorrow! They were delightful, not overly sweet but sweet enough, and the consistency of the crust was perfect. Thank you for this recipe!
Meymi
Hi Alexia, Thank you so much for your detailed feedback! I’m so happy to hear that it was a hit!
Kerstin Stiffler
So easy to make and absolutely delicious. This will be my go to recipe from now on. Thank you!
Meymi
Hi Kerstin, I’m thrilled to hear you loved this recipe so much! Thank you for your comment!
Sue Clements
I had a big bag of frozen blueberries in my freezer had all the ingredients so I gave it a try.
The blueberries had a lot of juice when they thawed so I added extra corn starch and doubled the recipe. Delish!
Meymi
Hi Sue, I’m so glad you enjoyed this recipe. You don’t need to thaw the blueberries before using. Thank you for your comment!
Joanne Taylor McKinnon
Honestly, these were amazing! I made them last week and am so glad I found this recipe again … I’ve printed it now!! Thanks so much, they turned out perfectly, I used fresh berries as suggested. PERFECT!
Meymi
Hi Joanne, I’m thrilled to hear you enjoyed this recipe so much! Thank you for your comment!
Ashley
Sooooooo good!!! We added cherries from the farmers market and it was delicious! Will absolutely make this again!
Meymi
Hi Ashley, I’m so happy that you love these bars so much! Thank you for your feedback!
Jody
What size pan to use if doubling this recipe?
Meymi
Hi Jody, You can use a 9*13 inch pan.
Joanne Emmons
Could you use oat flour in this recipe instead of all-purpose? If so, would I need to add any additional binding ingredient?
Meymi
Hi Joanne, I haven’t tried with oat flour but one of my readers shared that she used oat flour instead of all purpose flour. You can see it in the first comment.
Courtney
I don’t usually leave comments or reviews; but thank you so much for this recipe! It’s so good!!! I’m going to try it with cranberries as well during Christmas to see how that turns out.
FYI I used frozen blueberries and just added a little bit more of the cornstarch so the blueberry batter didn’t get too mushy. It turned out soo good. I am saving this recipe and will be trying it with cranberries during Christmas to see how it turns out. Thank you 🙂
Meymi
Hi Courtney, I’m so happy to hear you loved this recipe so much🙂 I’ll be glad if you share how it turns out with cranberries. Thank you for your comment!
Jody
Just made these and they are wonderful. I didn’t have a lemon so I substituted orange zest and juice. Thanks for a lovely recipe!
Meymi
Hi Jody, I’m thrilled to hear you loved these bars so much. Thank you for your feedback!
Jane
I just made these to bring out to my son’s and his family. OMG….had to taste one. Absolutely delicious. Thank you for the great recipe. ❤️
Meymi
Hi Jane, I’m so happy to hear you loved this recipe so much! Thank you for your comment!