Oat Flour Blueberry Crumble Squares
Oat flour makes these squares way more tender than regular flour versions. The crumb topping gets golden and crunchy while the blueberry layer stays jammy.
You’ll cut them into perfect squares that actually hold together instead of crumbling apart.
Why Oat Flour Changes Everything
Oat flour absorbs moisture differently than wheat flour, creating a softer base that won’t get tough. It also adds a subtle nutty sweetness that pairs perfectly with tart blueberries. Make your own by grinding old-fashioned oats in a food processor until fine, or buy it pre-made.
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Press That Bottom Layer Firmly
Pack the base mixture into your pan like you’re making a pie crust. Use the bottom of a measuring cup to press it down evenly. This prevents soggy bottoms and creates a sturdy foundation that won’t fall apart when you cut the squares.
Crumble Texture Depends on Butter Temperature
Cold butter creates distinct crumble pieces that stay separate during baking. Room temperature butter will mix too smoothly and won’t give you those coveted chunky bits on top. Cut your butter into small cubes and keep it chilled until you’re ready to mix.
Getting Clean Square Cuts
- Chill the baked squares for 30 minutes before cutting – this firms up the blueberry layer and prevents messy cuts.
- Wipe your knife clean between cuts to avoid dragging blueberry filling across the crumble topping.
Frequently Asked Questions
Will frozen blueberries work in this recipe?
Yes, but don’t thaw them first. Toss frozen berries directly with the cornstarch mixture to prevent excess moisture from making the base soggy.
How long do these squares stay fresh?
Store covered at room temperature for 3 days or refrigerate for up to a week. The texture stays best at room temperature.
What if I don’t have oat flour?
Grind 2 cups old-fashioned oats in a food processor for 30-60 seconds until you get a fine flour consistency.
Must-Have Items
Oat Flour Blueberry Crumble Squares
Ingredients
Filling
Equipment Needed
- 9×9-inch baking pan
- Food processor or pastry cutter
- Medium mixing bowl
Instructions
- Prepare pan: Preheat oven to 350°F. Line a 9×9-inch baking pan with parchment paper, leaving overhang for easy removal.
- Make crumble mixture: In a large bowl, combine oat flour, oats, brown sugar, and salt. Cut in cold butter using a pastry cutter or your fingers until mixture resembles coarse crumbs with some pea-sized butter pieces.
- Form base layer: Reserve 1 cup of the crumble mixture for topping. Press remaining mixture firmly into prepared pan using the bottom of a measuring cup.
- Prepare blueberry filling: In a medium bowl, gently toss blueberries with granulated sugar, cornstarch, lemon juice, and vanilla until evenly coated.
- Assemble squares: Spread blueberry mixture evenly over pressed base. Sprinkle reserved crumble mixture on top.
- Bake and cool: Bake for 35-40 minutes until top is golden brown and blueberry filling is bubbling. Cool completely in pan before cutting into squares.
Nutrition Facts
Per Serving (1 square)
