This Blueberry Crumble Slice are moreish little bites bursting with jammy juicy blueberry flavour. The biscuit base is actually just a compressed version of the crumble topping – super easy to make and something the whole family will love!

Blueberry Crumble Slice. The biscuit base is actually just a compressed version of the crumble topping - super easy!

I’m back with the crumble again.  I can’t seem to stop.  I think I may be starting to like crumble topping more than….


No it can’t be.  After all I’m a self confessed chocoholic.  I could probably count on one hand the number of days I haven’t eaten chocolate in the last 6 months.  They say the first step to dealing with an addiction is to admit it to yourself.  Well I do admit it.

I just don’t see it as a problem.

I wonder how chocolate crumble would taste?

I’ll try to push that though out of my mind, but in reality I know that the part of my brain responsible for my chocolate addiction is biding it’s time before flooding my head with the desire to go and make it.

I have to say, it’ll be hard-pressed to beat this crunchy, juicy blueberry crumble slice though.  I first saw the recipe for this on a blog call Flavour Mosaic.  The pictures of the juicy jamminess of the blueberries went straight on one of my pinterest boards and I kept going back and drooling over it until I made it.  And then I made it two more times in the same week.

One of the things that totally stood out for me was that the base of the crumble slice is made up of exactly the same ingredients as the topping.  Just squashed together more.  Double crumble whammy yay!
I made a few small adjustments to quantities, and I also made a bigger batch to fit my baking tray.  My tray is 32.5cm(12.8″)x18.5cm(7.3″) with a depth of 3.5cm(1.4″).  Don’t worry too much about the sizes though.  You could got for a smaller-but-deeper bake if you wanted.  It’ll just need a bit longer in the oven.  Or you could go for a square or round baking tin so long as your base comes in at around 500cm-600cm squared.  I like to cut my slices into small squares.  So I end up with 32 little slices out of this.  Of course, you can go bigger and get 18 slices out of it if you wish.

For this recipe, you’re simply going to make the crumble mixture in one bowl.  Then spoon out half of it into your baking tray and squash it down into a kind of crumbly biscuit.  Then you’re going to combine sugar, lemon juice, cornstarch and blueberries and layer this on your base.  The addition of the cornstarch is what helps to create that glossy, jammy look, and also stops the blueberries from just turning to liquid and seeping into the base.  Finally you’ll sprinkly the remaining crumble mixture on top, and bake until the topping is golden brown.

The Blueberry Crumble Slice Recipe:

5 from 2 votes

Blueberry Crumble Bake

This Blueberry Crumble Slice are moreish little bites bursting with jammy juicy blueberry flavour. The biscuit base is actually just a compressed version of the crumble topping - super easy to make and something the whole family will love!
Prep Time: 15 minutes
Cook Time: 40 minutes
Total Time: 55 minutes
Servings: 32 bite-sized slices
Course: Dessert
Cuisine: British


Crumble base and topping:

  • 360 g (3 cups) plain (all-purpose) flour
  • 1 tsp baking powder
  • 230 g (1 cup minus 2 tsp) cold butter cut into small cubes
  • 120 g (1/2 cup + 1 1/2 tbsp) white sugar
  • 120 g (1/2 cup + 1 1/2 tbsp) light brown sugar
  • ½ tsp salt
  • 1 large egg beaten
  • 1 tsp vanilla extract

Blueberry Filling:

  • 450 g (2 1/2 cups) blueberries
  • 120 g (1/2 cup + 1 1/2 tbsp) white sugar
  • 2 tsp lemon juice
  • 3 tsp cornstarch
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  • Preheat your oven to 190C/375F (fan). Line a 32.5cm(12.8")x 18.5cm(7.3") tray with baking parchment and put to one side.
  • First, make your crumble. Place the flour, baking powder, and cold butter cubes in a large bowl. Rub the butter into the flour using your fingertips until the mix resembles breadcrumbs. Don't worry if you have some large chunks in there - it adds to the texture. Add in the white and brown sugar, salt, egg, and vanilla extract, then give it a mix with your hands. Take approx. half of this mixture and place it into your prepared baking tray. Flatten the mixture down and squash it to the edges and corners.
    360 g (3 cups) plain (all-purpose) flour, 1 tsp baking powder, 230 g (1 cup minus 2 tsp) cold butter, 120 g (1/2 cup + 1 1/2 tbsp) white sugar, 120 g (1/2 cup + 1 1/2 tbsp) light brown sugar, 1/2 tsp salt, 1 large egg, 1 tsp vanilla extract
  • Take a medium-sized bow and add your blueberries, sugar, lemon juice, and cornstarch. Mix together gently and then layer this mixture on top of your crumble base. Sprinkle the remaining crumble mixture on top of the blueberries and place in the oven to cook for 40 minutes - until the topping looks golden brown.
    450 g (2 1/2 cups) blueberries, 120 g (1/2 cup + 1 1/2 tbsp) white sugar, 2 tsp lemon juice, 3 tsp cornstarch
  • Take out of the oven and leave to cool in the tin before gently sliding the bake (baking parchment too) onto a cutting board. Slide out the baking parchment and cut the bake into 32 bite-sized pieces or 18 larger pieces.


Wrapped in baking parchment and placed in a sealed container, this bake will keep for 2 days.


Serving: 46g | Calories: 147kcal | Carbohydrates: 22.2g | Protein: 1.5g | Fat: 6.2g | Saturated Fat: 3.8g | Cholesterol: 21mg | Sodium: 80mg | Potassium: 48mg | Fiber: 0.6g | Sugar: 12.6g | Vitamin A: 200IU | Vitamin C: 3.3mg | Calcium: 10mg | Iron: 0.7mg

Nutrition information is automatically calculated, so should only be used as an approximation.


p style=”text-align: center;”>  Nutritional info obtained from per serving (based on 32 bite-sized servings)


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Hi, I'm Nicky and I love to cook! I want to share with you my favourite, delicious family friendly recipes. I want to inspire you to create fantastic food for your family every day.

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  1. Suzanne says:

    5 stars
    I have made the blueberry crumble slice several times and it is always a winner with family and friends 👍

  2. David Turner says:

    Try using a mixture of apple and blueberries!!
    Yum!!! 🙂
    Lemon juice will add a sharpness that is cut through by the sweetness of the crumble mix!!
    It works really well!
    Add some naughtiness by adding a shot of good whisky (18 Year old fiddich for example) to the blueberry, apple and lemon mix)
    Tremendous!!!!!! 🙂
    Best wishes!!

  3. Eleanor says:

    5 stars
    Delicious treat, kids love them in their packed lunch.

  4. HostessAtHeart says:

    What a beautiful bakery! I don’t know if I could hold myself to a bite size piece though. I do love crumbles too!

    1. Nicky Corbishley says:

      I know what you mean! I think I actually end up eating twice as much when something’s bite-sized!

  5. Nicky Corbishley says:

    Thanks Christine, You’re right of course, double crumble’s a winner 🙂

  6. Christine says:

    This looks amazing! Nice thick layers and I love how you get twice as much crumble packed into one dessert. After all, that’s the best part!

  7. Ahu Shahrabani says:

    This looks amazing – beautiful photos! And I think you should give in to your thoughts and try the chocolate crumble 😉

    1. Nicky Corbishley says:

      oh go on then, you’ve talked me into it (that took a lot of persuasion didn’t it!!) 🙂

      1. ahu @ ahueats says:

        Haha! Waiting with bated breath to see the results 🙂