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Easy Blackberry Crumble Bars

If you love a crunchy breakfast bar, loaded with the flavor of blackberries, this is the recipe for you. A rich crumbly crust, a sticky middle, and a lovely streusel topping. . .all in one luscious bite. Best of all, it’s not overly sweet!

Is there Anything Finer than a Blackberry?

A friend recently gifted me several flats of fresh blackberries. I couldn’t wait to get my hands on them. I’m absolutely in love with blackberries. They’re my favorite berries ever!

I spent a couple days washing, drying, and freezing all of those berries. (We’re talking gallons here.) Then, right away, I made a Blackberry Cheesecake. It was sublime!

Easy Blackberry Crumble Bars from Out of the Box Baking.com

Still, with a freezer full of blackberries, what’s a girl to do? Come up with more recipes, of course. And that’s how I concocted this one. I love a good bar, especially one with a crumble topping.

What is a Crumble Bar?

A crumble bar is a cookie bar with streusel (crumble) on top. These are yummy any time of day but they’re reminiscent of coffee cake, so they’re particularly good in the morning.

One benefit of a bar instead of a piece of coffee cake is the convenience. They’re easy to make, easy to serve, and easy to hold in your hand. (No fork necessary!)

What is Streusel?

I love streusel topping so much that I devoted a whole post to it. Basically, it’s a crumbly topping that incorporates butter, sugar(s), oats, flour, and pecans.

What sets this particular recipe apart from others is that the bottom crust uses the same recipe as the streusel topping, with only two exceptions: the bottom has two eggs and vanilla, the topping does not.

I created the recipe that way on purpose so that I would have a simple formula I could always remember. I plan to use this recipe again and again. I’m just crazy about that crumble topping!

Are you ready to see what goes into these bars? These are such simple ingredients! You’ve probably already got most of them on hand. And don’t worry if you don’t have blackberries. Any berries will do!

Blackberry Crumble Bar Ingredients

You will find a full printable recipe card at the bottom of this post but here’s a quick peek at what you’ll need to make these delicious bars.

FOR THE CRUST

Easy Blackberry Crumble Bars from Out of the Box Baking.com
  • salted butter
  • white sugar
  • light brown sugar
  • room temperature eggs
  • all-purpose flour
  • oats
  • pecans
  • salt
  • vanilla extract

FOR THE FILLING

Easy Blackberry Crumble Bars from Out of the Box Baking.com
  • fresh blackberries
  • cornstarch
  • lemon zest
  • the juice of one lemon

FOR THE STREUSEL TOPPING

Easy Blackberry Crumble Bars from Out of the Box Baking.com

Same as crust but no eggs or vanilla

  • Butter
  • Brown sugar
  • White sugar
  • Oats
  • Pecans
  • flour
  • Pinch salt

How to Make Easy Blackberry Crumble Bars

These might look complicated but I promise they’re not!

Start by preheating your oven to 350 degrees Fahrenheit

Butter a 9 x 13-inch pan and set aside.

MAKE THE FILLING: 

Rinse two cups of blackberries and place in heavy saucepan over low-to-medium heat. 

Add sugar and lemon zest. 

Easy Blackberry Crumble Bars from Out of the Box Baking.com

In a separate small container mix cornstarch and lemon juice. (I added a little berry juice to mine so it wouldn’t be so thick.) 

Easy Blackberry Crumble Bars from Out of the Box Baking.com

Pour cornstarch liquid into pan after the berries start to break down. Stir well.

Easy Blackberry Crumble Bars from Out of the Box Baking.com

I had big (chunky) blackberries, so I used my pampered chef meat chopper to break them down. Allow to simmer. Stir and remove from heat. Allow to cool. 

MAKE THE CRUST: 

Cream butter until light and fluffy. Add sugars and vanilla and mix well. (If you like, you can use a food processor instead of a mixer.)

Easy Blackberry Crumble Bars from Out of the Box Baking.com

Add eggs and mix well. 

Easy Blackberry Crumble Bars from Out of the Box Baking.com

Add dry ingredients (oats, flour, and salt). Mix until fully incorporated, but don’t over mix. 

Easy Blackberry Crumble Bars from Out of the Box Baking.com

Fold in pecans. 

Press dough into the bottom of a prepared 9 x 13-inch pan. If you like, you can line the pan with parchment paper for easy lifting.

Easy Blackberry Crumble Bars from Out of the Box Baking.com

(Note: I used an 8 x 10-inch pan because it’s what I had handy, but if you want a thinner square use the larger pan.) 

Place in refrigerator. 

MAKE THE STREUSEL:

The crumble mixture is exactly like the crust except you don’t add any eggs or vanilla. 

Cream butter and add sugars. Mix well. 

Add oats, flour, and salt. Mix well. 

Add chopped nuts. 

Easy Blackberry Crumble Bars from Out of the Box Baking.com

You’ll end up with a crumbly/mealy texture, which is perfect. You want it to be able to run through your fingers. 

ASSEMBLE THE BARS

Pull the crust from the fridge. Pour the blackberry filling over it, spreading almost to the edges but not quite.

Easy Blackberry Crumble Bars from Out of the Box Baking.com

Add the crumble. If you’re using a 9 x 13-inch pan you might be able to use it all, but I had a full cup of crumble left over since I used a smaller pan. Place any remaining crumble mixture into a baggie and store in the refrigerator or freezer. (It should be good for several weeks in the fridge and a couple months in the freezer.) See my post on streusel to discover other uses for streusel. 

Easy Blackberry Crumble Bars from Out of the Box Baking.com

Place crumble in a preheated oven and bake for 30 minutes or until golden. 

Easy Blackberry Crumble Bars from Out of the Box Baking.com

Remove from oven and place on wire rack to cool. 

Once fully cooled, cut into squares. 

Easy Blackberry Crumble Bars from Out of the Box Baking.com

If you like, you can drizzle lemon glaze over the top. To make a glaze you can mix lemon juice and powdered sugar. If you like, you can serve with a scoop of ice cream.

These will stay fresh up to two days at room temperature and longer in the refrigerator but your streusel might lost its crispness in the fridge.

Don’t cover with plastic wrap until you’re 100% convinced it has cooled to room temperature. Any moisture caused from warm bars will cause the topping to go soggy. One it’s completely cooled, place in an airtight container or cover with cling wrap.

See this recipe at

Full Plate Thursday 

Weekend Potluck

Busy Monday

What to Expect from These Delicious Blackberry Crumb Bars

Easy Blackberry Crumble Bars from Out of the Box Baking.com

This is an easy to manage bar, in spite of the crumbly top. It’s not overly sweet and the gooey texture in the middle adds just the right amount of sweetness. There’s a reason blackberry season is my favorite!

I personally love the crunch of the nuts in the streusel. If you’ve followed me for any length of time you know I’m nuts about nuts.

These were easy to cook, easy to cut, and easy to eat. All in all, an easy treat, perfect with a cup of coffee or as an afternoon snack. And that buttery crumble is just perfect!

And, as I mentioned above, you can also serve this dish as a dessert with a scoop of vanilla ice cream. Yum! This is the perfect summer dessert, but don’t wait until summer to make it!

Variations on this Recipe

Easy Blackberry Crumble Bars from Out of the Box Baking.com

I would imagine I’ll be making these easy bars a lot for breakfasts or brunches. Here are some ways I might change things up next time. I might add:

Fresh or frozen blueberries: You can make the same filling using blueberries in place of blackberries. 

Fresh or frozen strawberries: Make as directed. Lemon and strawberry pair well together. Make sure you let the berries break down so the filling is easier to spread. 

Fresh or frozen raspberries: Make as directed. 

Fresh or frozen cranberries: This one’s a little different. Cook in half a cup of water until the berries pop. Add orange juice and zest in place of lemon.

Fresh or frozen (pitted) cherries: I would probably skip the lemon zest and juice and opt for a couple tablespoons of water to help the cherries break down. It might be fun to add half a cup of mini chocolate chips along with the cherry filling. 

Fresh diced apples: Simmer with a couple teaspoons butter, a pinch of cinnamon and sugar. 

Preserves: You can use a full jar of preserves or curd in any flavor you like. 

Pie filling. You can use pie filling but be sure to chop/mix the fruit into smaller pieces so it’s spreadable. 

Questions People are Asking about Blackberry Bars

Can I use cold butter in place of room temperature?

Yes, but you might opt to grate it with a cheese grater first for easier mixing.

How can I use up any leftover crumble?

I have a whole post dedicated to streusel and I offer many suggestions there.

Do I have to use fresh berries?

No, frozen blackberries will work just fine.

Can I use a pastry blender (or pastry cutter) in place of a mixer?

Absolutely. Just make sure you end up with a crumble streusel, one you can sprinkle on top and then press down.

Other Fruit Desserts from Out of the Box Baking

I have a lot of fruit themed desserts. Here are some of my favorites:


About the Author

Janice Thompson is an author, baker, and all-around mischief maker! She has overcome a host of baking catastrophes, including a toppled wedding cake, to learn more about the baking process. Janice has published over 150 books for the Christian market but particularly enjoys writing recipes and baking devotions. To learn more about Janice or to drop her a note, visit her About the Author page.

Easy Blackberry Crumble Bars

Easy Blackberry Crumble Bars

Yield: 24
Prep Time: 10 minutes
Cook Time: 30 minutes
Total Time: 40 minutes

If you love a crunchy breakfast bar, loaded with the flavor of blackberries, this is the recipe for you. A rich crumbly crust, a sticky middle, and a lovely streusel topping. . .all in one luscious bite. Best of all, it's not overly sweet!

Ingredients

  • Blackberry Crumble Bars Ingredients
  • FOR THE CRUST:
  • 1/2 cup oats
  • 1/2 cup butter
  • 1/2 cup white sugar
  • 1/2 cup brown sugar
  • 1/2 cup chopped pecans
  • 1 cup flour
  • Pinch salt
  • 2 eggs
  • Vanilla
  • FOR THE FILLING
  • 2 cups fresh blackberries
  • 2 tablespoons cornstarch
  • Lemon zest
  • Lemon juice (one)
  • FOR THE STREUSEL
  • Same as crust but no eggs or vanilla
  • 1/2 cup butter
  • 1/2 cup brown sugar
  • 1/2 cup white sugar
  • 1/2 cup rolled oats
  • 1/2 cup chopped Pecans
  • 1 cup all purpose flour
  • Pinch salt

Instructions

  1. Preheat oven to 350 degrees Fahrenheit
    Butter a 9 x 13-inch pan.

    MAKE THE FILLING:
    Rinse two cups of blackberries and place in heavy saucepan over low-to-medium heat.
    Add sugar and lemon zest.
    In a separate small container mix cornstarch and lemon juice. (I added a little berry juice to mine so it wouldn’t be so thick.)
    Pour cornstarch liquid into pan after the berries start to break down.
    I had big (chunky) blackberries, so I used my pampered chef meat chopper to break them down. Allow to simmer. Stir and remove from heat. Allow to cool.

    MAKE THE CRUST:
    Cream butter until light and fluffy.
    Add sugars and vanilla and mix well.
    Add eggs and mix well.
    Add oats, flour, and salt. Mix until fully incorporated, but don’t over mix.
    Fold in pecans.
    Press dough into the bottom of a prepared 9 x 13-inch pan.
    (Note: I used an 8 x 10-inch pan because it’s what I had handy, but if you want a thinner square use the larger pan.)
    Place in refrigerator.

    MAKE THE CRUMB:
    The crumb is exactly like the crust except there’s no egg or vanilla.
    Cream butter and add sugars. Mix well.
    Add oats, flour, and salt. Mix well.
    Add chopped nuts.
    You’ll end up with a crumbly/mealy texture, which is perfect. You want it to be able to run through your fingers.

    ASSEMBLE THE BARS
    Pull the crust from the fridge
    Pour the filling over it, spreading almost to the edges but not quite.
    Add the crumble. If you’re using a 9 x 13-inch pan you might be able to use it all, but I had a full cup of crumble left over since I used a smaller pan. Place it in a baggie and store in the freezer. (It should be good for a couple months in the freezer.) See my post on streusel to discover other uses for streusel.

    Place crumble in a preheated oven and bake for 30 minutes or until golden.
    Remove from oven and place on wire rack to cool.
    Once fully cooled, cut into squares.

    If you like, you can drizzle lemon glaze over the top. To make a glaze you can mix lemon juice and powdered sugar.

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