Go Back
Mixed Berry Crumble Bars

Mixed Berry Crumble Bars

These oatmeal berry bars are the kind of recipe you'll come back to all summer long. A buttery, golden oat crumble sandwiches a jammy, lemon-kissed berry filling that bubbles up perfectly in the oven. Ready in under 45 minutes, naturally adaptable to gluten-free, and just as welcome at breakfast as they are for dessert.
Print Recipe Pin Recipe
Prep Time 10 minutes
Cook Time 30 minutes
Total Time 40 minutes
Servings 9

Ingredients
  

Berry Filling

  • cups mixed fresh berries
  • 2 tbsp white granulated sugar adjust up or down based on berry sweetness
  • 1 tbsp fresh lemon juice freshly squeezed preferred
  • 1 tbsp cornstarch or substitute a small amount of all-purpose flour

Oat Crumble

  • 1.5 cups quick oats rolled oats work but quick oats give better structure
  • 1 cup all-purpose flour or 1:1 gluten-free baking flour
  • ⅔ cup light brown sugar packed
  • ½ tsp ground cinnamon add a pinch of nutmeg if desired
  • ½ tsp baking powder make sure it's fresh
  • ¼ tsp sea salt
  • ½ cup unsalted butter melted and cooled
  • 1 tsp pure vanilla extract

Instructions
 

  • Group 1 — Make the Berry Filling
    1. Add the berries, white sugar, lemon juice, and cornstarch to a medium bowl. Stir gently until the berries are evenly coated. Set aside. If using frozen berries, thaw and drain completely before mixing.
    Group 2 — Make the Oat Crumble
    2. Preheat your oven to 375°F (190°C). Line an 8×8 inch baking pan with parchment paper and set aside.
    3. In a large mixing bowl, whisk together the quick oats, flour, brown sugar, cinnamon, baking powder, and salt until well combined.
    4. Pour in the melted butter and vanilla extract. Stir until the mixture is evenly moistened and forms a crumbly, slightly clumpy dough.
    Group 3 — Assemble
    5. Press approximately two-thirds of the oat crumble firmly and evenly into the bottom of the prepared pan to form the base layer.
    6. Spoon the berry filling over the oat base and spread it out into an even layer, all the way to the edges.
    7. Sprinkle the remaining oat crumble evenly over the top of the berries.
    Group 4 — Bake and Cool
    8. Bake for 28 to 32 minutes, until the top crumble is golden brown and the berry filling is bubbling around the edges.
    9. Remove from the oven and allow the bars to cool completely in the pan before slicing — at least 1 hour at room temperature, or refrigerate for 2 to 3 hours for the cleanest cuts.

Notes

  • Adjust sweetness to your berries. In-season berries at peak ripeness need less sugar. Tart or out-of-season berries may need an extra tablespoon.
  • For clean slices, refrigerate the fully cooled bars for 2–3 hours before cutting. Run your knife under hot water before each slice and wipe the blade clean between cuts.
  • Gluten-free option: Use certified gluten-free quick oats and a 1:1 gluten-free all-purpose flour. No other changes needed.
  • Dairy-free option: Substitute melted coconut oil or a plant-based butter in equal measure.
  • Storage: Keep in an airtight container in the refrigerator for up to 1 week, or freeze individually wrapped bars for up to 3 months.
  • Serving ideas: Warm for 20 seconds in the microwave and top with vanilla ice cream, whipped cream, or crumble over yogurt for a quick parfait.
 

Nutrition

Calories: 334kcal, Carbohydrates: 42g, Protein: 4g, Fat: 18g, Saturated Fat: 10g, Cholesterol: 41mg, Sodium: 241mg, Potassium: 180mg, Fiber: 3g, Sugar: 24g, Vitamin A: 488IU, Vitamin C: 1mg, Calcium: 57mg, Iron: 1mg
Nutrition information is automatically calculated and should only be used as an approximation.
Keyword berry crumble bars, easy berry dessert, gluten free option, oat bars, oatmeal berry bars, summer berry recipe