Name: Blackberry Crumble Bars
Prep time: 20 min
Cook time: 50 min
Total time: 1 h 10 min
Yield: 16
Ingredients: 188g (1 ½ cup) all-purpose flour; 45g (½ cup) old-fashioned oats; 65g (⅓ cup) soft brown sugar; ½ teaspoon baking powder; ½ teaspoon salt; 140g (10 Tablespoons) unsalted butter, melted; 310g (2 ½ cups) fresh or frozen blackberries; 65g (⅓ cup) granulated sugar; 1 tablespoon cornstarch; ½ tablespoon lemon juice; 1 teaspoon vanilla; 1/2 teaspoon cinnamon; 1/4 teaspoon salt

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These blackberry crumble bars have a jammy blackberry filling made with frozen or fresh blackberries, a buttery base, and a crumble top.

I love these blackberry crumb bars because they taste great and are easy! The base and the buttery crumble topping are made from the same dough.

The blackberry mixture used as the filling is sweet, slightly tangy, and tastes like blackberry pie. You can use any of your favorite berries if you don’t have blackberries. I have a raspberry crumble bar version too.

Ingredients

Here are the ingredients needed for these blackberry bars. Find the full recipe and the amounts written in the recipe card at the bottom of this post.

Juicy blackberries (use fresh berries or frozen). Sweet blackberries make a delicious contrast to the buttery crumble. They’re also such a pretty purple!
Light brown sugar. Adds sweetness and a hint of molasses.
Lemon juice enhances the blackberry flavor
Cinnamon – Just a little bit to add flavor.
Purpose flour: The base structure.
Old-fashioned oats: Brings texure
Baking powder: For a little lift
Butter: Melted butter brings all the flavor.
Vanilla extract: This is added to the blackberry filling
Cornstarch: Thickens the filling.
Salt: To balance the sweetness.

Equipment

8×8 square pan lined with parchment paper.

Method

Crumb mixture

Preheat the oven to 350°F/180°C

Grease and line an 8×8 square baking pan with parchment paper. Leave an overhang of parchment paper to lift the bars out once baked and cooled easily.

Whisk together the dry ingredients in a large bowl – flour, oats, brown sugar, and baking powder.

Pour the melted butter into the flour mixture.

Use a fork to combine it into a thick and crumbly dough.

Press two-thirds of the oat mixture into the bottom of the pan to form the bottom crust.

Par-bake the crust in the preheated oven for 15 minutes, and prepare the berry filling while baking.

Blackberry jam

Combine blackberries, sugar, lemon juice, cinnamon, vanilla, cornstarch, and salt in a medium saucepan. Stir to combine.

Place the pan over low-medium heat, stirring regularly while the juices of the blackberries start to release.

Let the mixture come to a simmer, then boil for around 2 minutes, stirring continuously until it’s thick and glossy.

Remove it from the heat.

Assembling

Remove the par-baked base from the oven and carefully spread over the blackberry mixture into an even layer using the back of a spoon.

Crumble over the remaining crumble mixture over top.

Place it back in the oven and bake for 35 minutes until bubbling and golden brown on top.

Remove it from the oven and place on a wire rack. Let it cool to room temperature before removing it from the pan and slicing it into 16 individual bars.

Serve cold or slightly warm with a scoop of vanilla ice cream.

Store leftover blackberry crumb bars in an airtight container in the refrigerator for up to 5 days. They can also be frozen in a freezer-safe container for up to 2 months.

More berry desserts

Blackberry Crumble Bars

Yield: 16

Prep Time: 20 minutes

Cook Time: 50 minutes

Total Time: 1 hour 10 minutes

These blackberry crumble bars have a jammy blackberry filling made with frozen or fresh blackberries, a buttery base, and a crumble top.

Ingredients

Base and topping

188g (1 ½ cup) all-purpose flour
45g (½ cup) old-fashioned oats
65g (⅓ cup) soft brown sugar
½ teaspoon baking powder
½ teaspoon salt
140g (10 Tablespoons) unsalted butter, melted

Blackberry filling

310g (2 ½ cups) fresh or frozen blackberries
65g (⅓ cup) granulated sugar
1 tablespoon cornstarch
½ tablespoon lemon juice
1 teaspoon vanilla
1/2 teaspoon cinnamon
1/4 teaspoon salt

Instructions

Preheat the oven to 350°F/180°C
Grease and line an 8x8 square baking pan with parchment paper. Leave an overhang of parchment paper to lift the bars out once baked and cooled easily.
Mix the dry ingredients in a large bowl - flour, oats, brown sugar, salt and baking powder.
Pour in the melted butter. Use a fork to combine it into a thick and crumbly dough.
Press two-thirds of the oat mixture into the bottom of the pan to form the bottom crust. Par-bake the crust for 15 minutes, and prepare the berry filling while baking.

Blackberry filling

Combine blackberries, sugar, lemon juice, cinnamon, vanilla, cornstarch, and salt in a medium saucepan. Stir to combine.
Place the pan over low-medium heat, stirring regularly while the juices of the blackberries start to release.
Let the mixture come to a simmer, then boil for around 2 minutes, stirring continuously until it's thick and glossy. Remove it from the heat.
Spread the blackberry mixture over the par-baked base using the back of a spoon to ensure it's even.
Crumble the remaining crumb mixture on top.
Place it back in the oven and bake for 35 minutes until bubbling and golden brown on top.
Remove it from the oven and let it cool to room temperature before removing it from the pan and slicing it into 16.

Blackberry Crumble Bars