Prep time: 10 min
Cook time: 25 min
Total time: 35 min
Cuisine: American
Ingredients: 1 cup all-purpose flour; 1/2 cup brown sugar; 1/2 cup butter, softened; 1/4 cup pistachio pudding mix; 1/4 cup chopped pistachios; 1/2 tsp vanilla extract; 1/2 tsp baking powder; Pinch of salt

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Short Description
Pistachio Crumble Bars are buttery, nutty, and bursting with juicy blackberry flavor. With a tender oat base, a fruity filling, and a pistachio-studded crumble topping, these bars offer the perfect balance of sweet, tart, and crunchy in every bite.

Why You’ll Love This Recipe

These bars are an ideal treat for any occasion—from afternoon snacks to elegant dessert trays. The richness of pistachios combined with the vibrant flavor of blackberries creates a unique and satisfying dessert. They are also easy to make, customizable, and store well for days of enjoyment.

Ingredients

(Tip: You can find the complete list of ingredients and their measurements in the recipe card below.)

1 cup unsalted butter, melted and cooled
1 cup light brown sugar, loosely packed
1 teaspoon vanilla extract
1 1/2 cups old-fashioned rolled oats
1 1/4 cups all-purpose flour
1/2 teaspoon ground cinnamon
1/2 teaspoon baking soda
3/4 teaspoon salt
1/2 cup roasted, salted pistachios, coarsely chopped
12 ounces blackberries
1 tablespoon cornstarch
1 tablespoon granulated sugar
1 tablespoon lemon juice
Flaky sea salt (optional, for finishing)

Directions

In a large bowl, whisk together the melted butter, brown sugar, and vanilla until smooth.
In another bowl, combine oats, flour, cinnamon, baking soda, and salt. Add dry ingredients to wet and mix until combined. Fold in chopped pistachios. Let rest for 5 minutes.
In a separate bowl, gently toss blackberries with cornstarch, sugar, lemon juice, and a pinch of salt.
Preheat oven to 350°F (175°C). Line an 8×8-inch pan with parchment paper and grease it lightly.
Press a little over half the oat mixture into the pan to form the crust. Spread blackberry filling over it. Crumble the remaining oat mixture on top.
Bake for 35 minutes, until the top is golden and filling is bubbly.
Cool completely in the pan, then lift out using the parchment and cut into bars. Sprinkle with flaky sea salt if desired.

Servings and Timing

Servings: Approximately 9 bars
Prep Time: 20 minutes
Cook Time: 35 minutes
Total Time: 55 minutes (plus cooling)

Variations

Fruit Substitutions: Replace blackberries with raspberries, blueberries, or mixed berries.
Nut Alternatives: Almonds or walnuts can be used instead of pistachios.
Gluten-Free Option: Use a gluten-free flour blend in place of all-purpose flour.

Storage/Reheating

Storage: Keep in an airtight container at room temperature for up to 2 days, or refrigerate for up to 1 week.
Reheating: Warm individual bars in the microwave for 10–15 seconds if desired, although they are delicious at room temperature.

FAQs

What type of oats should I use for this recipe?

Old-fashioned rolled oats are ideal for texture. Avoid quick oats as they can make the bars mushy.

Can I use frozen berries instead of fresh ones?

Yes, frozen berries work well. Do not thaw them before mixing, and bake a few extra minutes if needed.

How do I prevent the crust from becoming soggy?

Pre-bake the crust for 10 minutes before adding the filling to help maintain its firmness.

Can I reduce the sugar content in this recipe?

Yes, but reducing sugar may alter the texture. Try small adjustments to maintain balance.

Is it necessary to use lemon juice in the filling?

Lemon juice brightens the berry flavor but can be substituted with lime or orange juice if preferred.

How should I chop the pistachios?

Coarsely chop them to distribute evenly and maintain a pleasant crunch in every bite.

Can I add spices to the crumble mixture?

Yes, spices like nutmeg or cardamom can add warmth and complexity to the flavor.

What can I serve these bars with?

They pair well with vanilla ice cream, whipped cream, or a cup of hot tea or coffee.

Can I make these bars ahead of time?

Absolutely. They can be prepared a day in advance and stored covered until serving.

Are these bars freezer-friendly?

Yes, you can freeze them in a sealed container for up to 2 months. Thaw at room temperature before serving.

Conclusion

Pistachio Crumble Bars are a delightful combination of rich, buttery oats, tart berry filling, and crunchy pistachios. Perfect for entertaining or a cozy afternoon treat, they’re easy to make, customizable, and utterly irresistible. Whether enjoyed warm or cold, these bars are sure to become a favorite in your baking rotation.