Chocolate Toffee Crumble Bars

These chocolate crumble bars are made extra special with brown butter and a layer of toffee bits! They’re so easy to make but are so incredibly rich in flavor and texture. The molten chocolate center makes these bars OVER THE TOP good.

This post is sponsored by SunButter and all thoughts and opinions are my own. Thank you for supporting the brands that make Butternut Bakery possible!

Perfect chocolate crumble bars

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 nutty brown butter flavor.

As for the chocolate filling, a layer of creamy Chocolate SunButter is spread on top of the partially baked base. It adds SO much richness to these bars. It has an addicting almost marshmallowy flavor to it that I just love.

To kick up the chocolate flavor even more, a layer of semisweet chocolate chips are sprinkled on top. Then to pair with the brown butter flavor, a layer of toffee bits are sprinkled on top.

When the chocolate filling is assembled, the rest of the crumble is sprinkled on top.

Once baked, the crust remains perfectly tender and the filling turns into this molten chocolate consistency that makes each bite so delicious.

a jar of chocolate sunbutter with crumble bar ingredients

chocolate sunbutter spread on a layer of crumble

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.
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 golden brown.
Cool – Allow the bars to cool before slicing, otherwise there’s a good chance they’ll fall apart.

the tops of sliced chocolate crumble bars

Chocolate Crumble Bars FAQs

Can these bars be made gluten free?

Although I haven’t tested it, I think it would work! Just swap the all-purpose flour with a cup-for-cup gluten free baking flour and make sure to use gluten free oats.

Can these bars be made vegan?

Yes and very easily! Just substitute plant-based butter and omit the toffee bits (or sub dairy free toffee).

Can I use old fashioned oats instead of quick oats?

Quick oats and old fashioned oats absorb water in different capacities, so it’s hard to sub one for the other. I don’t suggest making the swap but if you have to, pulse the old fashioned oats in a food processor a few times to break up into smaller pieces.

Would this recipe work with different chocolate chips?

Sure! You can also use dark chocolate chips but I don’t suggest using milk chocolate as it could make these bars too sweet.

How do you store chocolate crumble bars?

When the bars have completely cooled, they can be sliced and store in an air tight container in the refrigerator. They’ll keep for about 5 days.

a stack of chocolate crumble bars with a jar of sunbutter

For more chocolate recipes, check out my:

Make sure to tag me @butternutbakery on Instagram if you make these chocolate crumble bars. I love seeing my recipes come to life in YOUR kitchen! 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!