Blueberry oat squares are sweet, buttery, and delicious. With three mouthwatering layers, it has a soft and chewy crust, a sweet blueberry filling, and crumbly granola-like oat topping. Ready in just 45 minutes (including just 10-15 minutes of prep), these blueberry oat bars are the perfect late-night treat, prepped last-minute breakfast, and snack to feed your friends. However you serve the, they are always a crowd pleaser.
Why You’ll Love Blueberry Oat Squares
- Three mouthwatering layers. Similar to our Cranberry Sauce Oat Bars, these delicious squares have 3 layers of delicious goodness. First, there's a sweet and buttery crust layer of oats with a hint of vanilla. Then, a layer of fresh blueberries bathed in sweetness. And finally, top it all off with a cinnamon oat layer. It's a trio of perfection.
- It's easy yet fancy. These blueberry oat squares are ready in just 45 minutes, but look like they took hours. Plus, baking in a single pan makes them fast and easy to form into squares. Cut them smaller to serve a crowd (or kids), or indulge in a tray to yourself! Either way, it will be well worth the effort.
- Rolled oats make this dessert healthier. Although you’ll have to make an exception for the sugar, you’ll be adding nutrients to your diet by eating blueberries, and rolled oats—which is a much better alternative to a traditional cookie... right? At least that is what we like to think about our blueberry oat bars.
Ingredients and Substitutions
To make delicious blueberry oat squares, you will need the following ingredients:
- sugar - this recipe used both brown sugar and granulated sugar. Feel free to substitute the granulated sugar with brown sugar instead.
- rolled oats - make sure to use old fashioned rolled oats, don't use quick oats in this recipe because they are more fine like flour and will make the mixture dry.
- all-purpose flour
- vanilla extract
- baking powder
- blueberries - I recommend fresh blueberries if you want the blueberries to be more defined. You can also use frozen blueberries but the blueberry layer may be more jammy. If you are feeling adventurous and want to switch things up, you can also try substituting different berries or a berry blend with blackberries, raspberries, or strawberries.
- lemon juice
- cornstarch - helps to thicken the blueberry layer so that it won't be mushy.
- ground cinnamon
How to Make the Best Blueberry Oat Squares
- Make the crust layer. In a large bowl, use a hand mixer or stand mixer to cream together butter with brown sugar until light and fluffy. Add rolled oats, flour, vanilla, baking powder, and salt. Continue to mix until fully combined. The mixture will be slightly sticky. Transfer the mixture into a 9-inch square baking pan, and firmly press it in to create an even layer on the bottom.
- Make the blueberry layer. In a large mixing bowl, add all the ingredients for the blueberry layer (blueberries, sugar, lemon juice, and cornstarch). Gently toss to combine. Evenly distribute the blueberry mixture over the crust.
- Make the oat layer. In a shallow saucepan, melt butter over medium heat. Once melted, remove from heat and stir in oats, sugar, and cinnamon. Stir until fully combined. Sprinkle and evenly distribute the topping on top of the blueberry layer.
- Bake. Bake in a 350 F preheated oven for 30 to 35 minutes until lightly browned. Place on a wire cooling rack to cool down completely and cut into 9 even squares. Serve on its own or with a scoop of vanilla ice cream.
Recipe Tips and Tricks
- Wait before you slice: Feeling impatient? Don’t buy into your impulses. Wait for the blueberry oat squares to cool down completely before you cut them—or you could be looking at a drippy mess that ruins the square part of your oat squares.
- How to store: If you have any leftover oat squares, store in a single layer in an airtight container (or layer them with parchment paper in between to prevent sticking). They will keep at room temperature for up to 1-2 days or in the refrigerator for up to 5 days.
- How to freeze: Blueberry oat bars freeze really well and can be stored tightly wrapped in plastic cling wrap or in an airtight container for up to 3 months in the freezer. It's a great recipe to make a few batches of after a day of berry picking, freeze, and enjoy another day.
More Blueberry Recipes
- Lemon Blueberry Bread
- Blueberry Pie with Lattice Top
- Blueberry Yogurt Muffins
- Glazed Lemon Blueberry Scones
- Triple Berry French Toast
Did you make this recipe? I would greatly appreciate a comment and rating below, letting me know what you thought of the recipe. You can also snap a picture and tag me on Instagram @aheadofthyme or share it on the Pinterest pin so that I can follow along.