Brown Sugar Berry Crumble Bars

These deliciously jammy berry crumble bars are the perfect balance of sweet and tart. They have a triple berry filling made up of blackberries, raspberries, and strawberries in a buttery brown sugar crumble sandwich. The flavors are so perfect for berry season and they’re so easy to make!

Perfect berry crumble bars

I’m usually not one to go for fruity desserts, but this recipe is definitely the exception! The sweet and tart berries alongside the buttery brown sugar crumble is irresistible. Not to mention, they’re also SO quick and easy to make!

To start, the base and crumble topping are the same exact dough. This brown sugar crumble is mixed together and 2/3 is pressed into the bottom of the baking pan while the rest is crumbled on top. The flavors are buttery and sweet with that hint of molasses.

As for the triple berry filling, it comes together super quick by mashing together fresh raspberries and blackberries with a bit of brown sugar (just to cut through that tartness).

Once mashed, it’s mixed with cornstarch (to help thicken), lemon zest and juice (to bright up the flavors), vanilla, and (our third berry) strawberry preserves.

The preserves add another layer of sweetness while also acting as another thickening agent. The berry filling with look very thick, but it will thicken once baked!

And to make sure there’s a fresh berry in every bite, the filling is topped with a handful of extra fresh berries before adding the crumble on top.

Once baked, the crust remains perfectly tender and the filling turns into this thick and jammy consistency that makes each bite so delightful.

Tips for baking crumble bars

This is a very quick and easy recipe, but here are a few tips to ensure these turn out just right:

Flour – I say this in every post, and for good reason. It’s the number one reason why most recipes fail. If there’s too much flour, the crumble will turn out tough and dry. If possible, measure the flour with a food scale. Otherwise, to ensure the exact amount, gently spoon the flour into the measuring cup and level it off with a flat edge. If scooped directly into the flour container, the flour becomes packed down into the cup which could leave you with 1/4 cup or more of added flour.
Butter – When mixing in the melted butter, make sure it’s not piping hot. This could cause the sugar to dissolve which can lead to a different crumble texture.
Mixing – Thoroughly mix together the crumble to ensure everything is evenly moistened.
Mashing – When mashing the berries, make sure each berry gets at least one good mash with a fork. The mixture doesn’t have to be a puree, but it does have to be well mashed.
Crumble – Ensure the crumble covers every single square inch of that surface. This allows for the most even bake and the most delicious bars!
Done – The bars are done when the surface looks slightly darker (it won’t be golden), and the edges are just barely bubbling.
Cool – Allow the bars to cool before slicing, otherwise there’s a good chance they’ll fall apart.

Berry Crumble Bars FAQs

Can I use frozen berries?

Yes, just make sure to thaw them in a colander to drain any excess water. Then use as instructed.

Can I use different berries?

For the fresh fruit, I suggest sticking with raspberries and blackberries as these release a similar amount of juices. With that being said, you can choose to use all raspberries or all blackberries. For the preserves, use any flavor you like!

Can I use old fashioned oats instead of quick oats?

Unfortunately not, as old fashioned oats absorb liquid at a different capacity than quick oats.

Can this recipe be made vegan/dairy free?

Absolutely! Just swap the butter with plant-based butter and you’re good to go.

Can this recipe be made gluten free?

I haven’t tested it, but I think this recipe could work well with a cup for cup gluten free baking flour. Also make sure to use certified gluten free oats.

Can I use strawberry jam instead of preserves?

You can, but preserves are preferred for their texture and sweetness.

How do you store crumble bars?

Once the bars have baked and cooled, slice and store in a container in the refrigerator. They’ll keep for about 5 days.

Can this recipe be doubled for a 9×13 dish?

I think that could work! I suggest increasing the bake time by about 5-10 minutes.

For more berry dessert recipes, check out my:

Make sure to tag me @butternutbakery on Instagram and leave a review below if you make these berry crumble bars. To pin this recipe and save it for later, you can use the button on the recipe card, the buttons above or below this post, or on any of the photos above. Happy baking!

Watch how to make these berry crumble bars:

@butternutbakery
Brown sugar berry crumble bars!! So quick, so easy, and perfect for Easter.
♬ original sound – Jenna | Butternut Bakery