Gluten free Strawberry Rhubarb Crumble Slice. A dessert crumble bar made with a shortbread base, oat crumble top and a deliciously fruity compote. Perfect served with custard, ice cream or cream. Optional Dairy Free/Vegan
This post uses Affiliate links from which I may earn a small commission. As an Amazon Associate I also earn from qualifying purchases. Commission earned is at no extra cost to yourself. Thank you for supporting this blog.
DON’T LOSE THIS RECIPE… PIN IT FOR LATER…

Super-delicious Strawberry Rhubarb Crumble Slice
This Strawberry Rhubarb Crumble Slice is a delight. Super-yummy, it has a delicious gluten free shortbread base… This is followed by a thick compote layer of rhubarb and strawberry (mingled with a few whole blueberries)… All topped with a crunchy, oaty crumble. The tangy rhubarb is perfectly offset by the sweetness from the shortbread and crumble. And for optional extra flavour and interest, I have added some chopped nuts too.
Whether you love or hate rhubarb, this is most definitely a beautiful bake.




Seasonal rhubarb and how to enjoy it all year round
There’s no denying that rhubarb is a seasonal vegetable. The main season in the UK starts around April and although the best stalks are available through to the end of June, many plants will keep on producing well into the summer. Forced Rhubarb however is available much earlier… Often from as early as January in the UK, with Yorkshire forced rhubarb being particularly famed.
For those who have experienced forced rhubarb (which is grown by specific process), the difference is considerable. Not only is it sweeter and more delicate in flavour, but the colour stands out as the most vibrant and beautiful deep crimson pink.
But beyond the period of these growing seasons, what is the best way to preserve rhubarb for all year-round Strawberry Rhubarb Crumble Slice and other tangy recipes?
Well, it turns out it can be frozen in any number of ways.
Options for freezing rhubarb
- Raw – Cut into pieces. Then spread and fast-freeze (or flash-freeze) on open trays, before transferring to airtight freezer bags/containers.
- Blanched – Cut into pieces before blanching in boiling water for 1 minute. Immediately drain and plunge into ice-cold water to stop any further cooking. Pat dry with kitchen paper or a tea towel and then fast-freeze on open, lined trays in the same way as the raw rhubarb instructions above.
- Stewed – Lastly (and if you want to use it for crumble, Strawberry Rhubarb Crumble Bars, Rhubarb Curd or Rhubarb Compote) simply stew and freeze the rhubarb. Cut into pieces before adding to a sauce pan with a little sugar and a drop of liquid. Then cook over a low heat and simmer until tender. Freeze in a single tub or in portioned ice cube trays.




The Strawberry Combo in these Strawberry Rhubarb Crumble Bars
I have written about the Rhubarb-Strawberry combo before when I made Rhubarb, Strawberry & Cointreau Jam. Indeed, it was apparently first used for colour stability, ensuring the redness of strawberry remained on cooking. According to the Los Angeles Times, the acidity from the rhubarb helps to stabilise the strawberry’s red pigment, offering a more visually appealing result.
But wherever it started, Rhubarb and Strawberry have become a classic 21st Century pairing. The tanginess of the rhubarb being superbly tempered by the sweet fruitiness of the berries.
At Gluten Free Alchemist, we love the pairing. And in addition to Strawberry Rhubarb Crumble Slice, we have recipes for a gluten free Rhubarb Upside Down Cake with strawberry sponge; a totally divine Rhubarb and Strawberry Meringue Pie and a lovely Rhubarb, Strawberry and Pomegranate Jam.




Can I use this recipe for other fruit crumble bars?
If Strawberry Rhubarb Crumble Slice doesn’t appeal, then that’s fine. This recipe will work equally well as a base for other crumble bars too. Simply use the recipe for the shortbread base and crumble top and substitute the fruit in the compote layer for something you prefer.
Alternatively, we have other crumble slice-type recipes for gluten free Blackberry Apple Crumble Slice, a layered healthier Banana Flapjack Cake, some amazing Strawberry Crumble Muffins and even some incredible Chocolate Peanut Butter Oat Crumble Slices (which I really need to remake).




Ready to make Rhubarb Strawberry Crumble Slice?
But for now, here’s the recipe for Strawberry Rhubarb Crumble Slice. I hope you love it both for its gorgeous colour, and its amazing flavours. It needs no dressing up with fancy drizzles or sprinkles… But speaks temptingly for itself, promising you a combination of sweet and tart flavours, set against textures which are crisp, crunchy, soft, dry, moist and melty in each and every bite.
If you are tempted, then please give it a try. And let me know how you find it. Leave a comment. Tag me on Social Media (links at the top of the page). Send a message in a bottle… I just love hearing from you amazing people.
For everything else, head to our Gluten Free Recipe Index. Happy baking.








Other Rhubarb Recipes you might also like…
Strawberry Rhubarb Crumble Slice
Key equipment
- 8 inch/20 cm square baking tin
- oven + hob
- large sharp knife
Ingredients
Shortbread Base
- 220 g plain gluten free flour blend I used Gluten Free Alchemist blend A – See NOTES
- ½ tsp xanthan gum
- pinch fine sea salt
- 135 g unsalted butter (or dairy free alternative) cold and cubed
- 100 g golden caster sugar
Fruit Compote Layer
- 400 g fresh rhubarb cut into chunks (approx weight)
- 400 g strawberries hulled (approx weight)
- 2 to 3 tbsp soft light brown sugar
- handful fresh blueberries
Crumble Top
- 100 g gluten free oat flour Easy to make at home – See NOTES
- 80 g gluten free rolled oats
- 80 g unsalted butter (or dairy free alternative) cold and cubed
- 70 g soft light brown sugar
- 2 tbsp roasted chopped nuts optional
- + about a quarter of reserved base dough.
Instructions
Shortbread Base
- Base-line an 8 inch (20 cm) non-stick square tin (approx 5 cm/2 inch deep) with baking paper. Alternatively spray the base with non-stick baking release spray.
- Preheat the oven to 180 C/350 F/Gas 4.
- Weigh and mix in a large bowl the flour, salt and xanthan gum.
- Rub the butter into the flour until it resembles fine bread crumbs.
- Add and stir in the caster sugar.
- Remove ¼ of the mixture to a separate bowl and set aside (to be added later to the crumble topping).
- Press the remaining mixture together with hands to blend and form a loose dough.
- Tip the dough mixture into the base-lined/greased tin and press using the back of a spoon until even in the base of the tin and reasonably firm.
- Bake the base in the pre-heated oven for about 20 minutes, then remove and set aside to cool while you make the fruit and crumble layers.
Fruit Compote Layer
- Place your prepared rhubarb and strawberries (NOT the blueberries) with the brown sugar into a saucepan and gently heat, stirring, to bring to a simmer.
- Continue to simmer, stirring frequently until the mixture has reduced and thickened to an almost jam consistency.
- Remove from the heat and set aside to cool.
Oat Crumble Top
- Place the oat flour and oats in a large bowl and mix together.
- Add the butter cubes and rub into the flour until the mixture resembles coarse bread crumbs.
- Add the sugar, nuts (if using) and reserved dough from the base mix and stir through.
- Squeeze with finger tips until the mix has a slightly clumpy texture.
- Set aside.
Putting It All Together
- Re-heat the oven to 180 C/350 F/Gas 4.
- Spread the fruit compote layer on top of the shortbread base.
- Sprinkle the blueberries on top, followed by the oat crumble mix.
- You may wish to sprinkle a little extra brown sugar (optional) on top before placing the tin back in the oven.
- Bake for a further 20 to 25 minutes until golden.
- Take out of the oven and allow to cool completely in the tin, before removing and slicing into portions.
Notes
Nutrition
© 2019-2023 Kate Dowse All Rights Reserved – Do not copy or re-publish this recipe or any part of this recipe on any other blog, on social media or in a publication without the express permission of Gluten Free Alchemist
Strawberry Rhubarb Crumble Slice shared with
- Fiesta Friday #367 with Angie
- Full Plate Thursday #524 with Miz Helen’s Country Cottage
- Blogger’s Pit Stop #257
- Over The Moon #263 with Eclectic Red Barn and Marilyn’s Treats
- Sundays on Silverado #26 with The House on Silverado
Previously shared with – Baking Crumbs with Jo’s Kitchen Larder and Apply To Face Blog; What’s for Dinner #217 with The Lazy Gastronome
WOW this looks SO yummy! I’ve bookmarked to come back to later. Adrienne from Gluten Free Preppers and a member of the Blogger’s Pit Stop Crew
Thanks Adrienne. It’s such a lovely way to eat rhubarb and the combo with strawberry is always awesome x
I don’t eat gluten free, but this looked so delicious, I couldn’t resist pinning it! I’m coming to you from the Bloggers Pit Stop today. I love looking for new blogs and posts that catch my eye. This recipe certainly did that.
Thank you Christine for your lovely comment and for popping by. I totally agree. Bloggers Pit Stop has introduced me to lots of new blogs too.
This is one of those recipes that can be made GF or not I think. So we can all enjoy it xx
Awesome way to enjoy the classic strawberry-rhubarb combo, especially without gluten!
Thanks Irene. You can’t beat a crumble slice xx
These look so delicious, strawberry and rhubarb are fantastic together. Thank you for bringing your recipe to #CookBlogShare!
Thanks Monika. You're welcome. Strawberry & Rhubarb is one of my fave combos xx
Oooo these look delicious! Our rhubarb has disappeared for the winter, but I'll definitely be trying them next year when it pops back up. My SiL is coeilac, so they would be great for her.
I think maybe we have been lucky with the crop lasting that little longer. It is so yummy though I will be making it again next year too. Enjoy xx
This looks like a fancy version of the slices I grew up with! Am sure it tastes delicious esp with fruit from your garden. I am really looking forward to some summer fruits.
Good luck with your new venture – I am not great at keeping up with social media but will try and check it out as I am really interested to see how you go and wish you well – you have so much fantastic experience in GF baking, great photos and recipe, and have a lovely personable style that I hope takes you far
Awww thanks Johanna. It does all feel a little scary at the moment, but the opportunity has arisen for me to give it a go, so why not?! x
ooo yum! I love things like this, fruity and crunchy and brilliant!
Thanks Donna. Me too! So good! xx