Blueberry Lemon Oat Squares

Name: Blueberry Lemon Oat Squares
Prep time: 10 min
Cook time: 30 min
Total time: 40 min
Yield: 12 squares
Ingredients: 1 cup rolled oats; 1 cup whole wheat flour; 1/2 cup brown sugar; 1/4 cup melted coconut oil; 1/2 teaspoon baking soda; 1/4 teaspoon salt; 2 cups fresh blueberries; 1/4 cup honey; 1 tablespoon lemon juice; 1 tablespoon lemon zest; 1 tablespoon cornstarch

Highlighted under: Desserts Made Easy

I absolutely love making these Blueberry Lemon Oat Squares when I want a treat that feels wholesome yet indulgent. Combining nutty oats with the tangy flavors of fresh blueberries and lemon creates a refreshing snack that's perfect for any time of the day. Whether it's for breakfast, a midday pick-me-up, or a sweet dessert, these squares are always a hit. Plus, they’re easy to whip up and taste even better the next day, making them a great make-ahead option for busy days.

Created by

Ella Townsend

Last updated on 2026-02-08T00:09:36.435Z

Making these Blueberry Lemon Oat Squares has become a favorite ritual for me on weekends. The way the sweet blueberries burst and mingle with the zesty lemon filling is simply divine. I often play around with adding nuts or seeds for an extra crunch, which complements the soft texture of the oat base beautifully.

One tip I've found incredibly helpful is to use fresh lemon juice and zest for the best flavor. Pairing fresh ingredients really elevates the taste, making each bite a little sunshine in my mouth. I love to sprinkle a bit of powdered sugar on top just before serving for a touch of sweetness.

Why You'll Love These Squares
A delightful balance of sweet and tangy flavors
Healthy oats packed with nutrients and fiber
Easy to prepare – perfect for beginners!

Crafting the Perfect Crust

When preparing the crust for your Blueberry Lemon Oat Squares, achieving the right crumbly texture is key. Mix the dry ingredients thoroughly before adding the melted coconut oil. This ensures even distribution, preventing any oily clumps. Aim for a consistency that holds together when pressed but remains crumbly. If you find your mixture is too dry, a small splash of water can help bind the ingredients without compromising flavor.

It’s essential to press the crust evenly across the bottom of your baking dish. As you press, make sure to smooth out any bumps for even baking, which contributes to that beautiful golden finish. A flat-bottomed measuring cup works perfectly for this step, allowing for uniform pressure and preventing your crust from being dense in some areas and crumbly in others.

Perfecting the Blueberry Filling

For the blueberry filling, choosing ripe, juicy berries is vital for maximizing the flavor. Fresh blueberries will provide the best taste and texture, but if you need a substitute, frozen blueberries can work too. Just be sure to thaw and drain excess moisture before cooking. This prevents a watery filling that can make your oat squares soggy.

As you cook the filling over medium heat, keep an eye on the mixture until it starts bubbling; this indicates that the cornstarch is activating and thickening the filling. Stir occasionally to ensure even cooking and to prevent the berries from sticking to the bottom of the pan. Once it reaches your desired thickness—generally around 5-7 minutes—you'll be ready to pour it on the crust.

Ingredients

Gather all your ingredients before starting to ensure a smooth cooking experience!

For the crust and topping

1 cup rolled oats
1 cup whole wheat flour
1/2 cup brown sugar
1/4 cup melted coconut oil
1/2 teaspoon baking soda
1/4 teaspoon salt

For the filling

2 cups fresh blueberries
1/4 cup honey
1 tablespoon lemon juice
1 tablespoon lemon zest
1 tablespoon cornstarch

Make sure to measure everything accurately for the best results!

Instructions

Follow these steps to create your delicious Blueberry Lemon Oat Squares.

Prepare the crust

In a mixing bowl, combine rolled oats, whole wheat flour, brown sugar, melted coconut oil, baking soda, and salt. Mix until crumbly. Reserve about 1 cup of this mixture for topping.

Press into the pan

Grease an 8x8 inch baking dish and press the remaining oat mixture evenly into the bottom. Bake at 350°F (175°C) for 10 minutes.

Make the filling

In a saucepan, combine blueberries, honey, lemon juice, lemon zest, and cornstarch. Cook over medium heat until the mixture is bubbling and thickened, about 5-7 minutes.

Assemble and bake

Pour the blueberry filling over the baked crust, then sprinkle the reserved oat mixture on top. Return to the oven and bake for an additional 20 minutes.

Cool and serve

Let the squares cool completely in the pan before slicing into squares and serving.

Enjoy your freshly baked Blueberry Lemon Oat Squares!

Pro Tips

For added flavor, consider adding a pinch of cinnamon to the oat mixture or a handful of chopped nuts for crunch.

Storage and Make-Ahead Tips

These Blueberry Lemon Oat Squares can be made ahead of time, making them a convenient snack for busy days. After baking, let them cool completely in the pan, then transfer to an airtight container. They can be stored in the refrigerator for up to one week or frozen for up to three months. If freezing, cut the squares into portions and separate layers with parchment paper to prevent them from sticking together.

To revive the texture after freezing, simply reach for a square and leave it to thaw in the fridge overnight, or reheat briefly in the oven at 300°F (150°C) until warmed through. This way, you can enjoy that chewy, satisfying texture as if they were freshly baked each time.

Serving Suggestions

These oat squares can be served in various delightful ways. For a breakfast treat, consider adding a dollop of Greek yogurt on top or a drizzle of honey. If you're serving them as dessert, a scoop of vanilla ice cream can elevate the experience with a contrasting temperature and texture.

Feel free to experiment with add-ins for your filling, too! Chopped nuts or a sprinkle of seeds can provide an extra crunch, while a touch of cinnamon or nutmeg can enhance the flavor. These simple variations allow you to personalize the oat squares to your taste, making each batch uniquely yours.

Questions About Recipes

→ Can I use frozen blueberries?

Yes, but make sure to thaw and drain any excess moisture before using them.

→ How should I store leftovers?

Store leftovers in an airtight container in the fridge for up to 5 days.

→ Can I substitute the sugar?

Yes, you can use maple syrup or coconut sugar as alternatives.

→ Is it possible to make these gluten-free?

Yes, just replace the whole wheat flour with a gluten-free flour blend.