A quick and easy frozen fruit crumble with oats that is gluten and refined sugar-free. It makes a brilliant healthy and delicious pudding any time of the year. And can even help save a penny or two with the use of frozen fruit!

A healthier version of the traditional crumble, that is gluten and refined sugar-free. It uses sugar replacements, and almond flour alongside the ultimate fibre champions, oats. By using these ingredients instead of processed flours, butter and sugar can help as part of your overall diabetes management. We have certainly found that they work towards supporting a better balance with blood glucose levels.
However, if you prefer your crumble with the traditional apples then why not give my APPLE CRUMBLE WITH OATS a try as well.
What I love about this frozen fruit version of crumble with oats?
The use of frozen fruit in this crumble makes it quicker, easier, and cheaper. which are all great reasons to love it of course. But also I think the use of just berries or even frozen tropical fruits gives this dessert much more of a summer crumble feel to it.
Crumble is up there as one of my all-time favourite puds but the addition of frozen berries alongside the use of lemon instead of some of the more traditional spiced flavourings gives the stewed fruit a lovely tangy flavour. The fresh fruit and zesty lemon pairs beautifully with the sweet buttery crumble topping. It offers a refreshing change on a traditional crumble as well as making it a perfect pud to serve all year round!.
The additional step of pre-baking the oaty topping for 15 minutes gives this crumble an extra deliciously crumbly topping. Which I think is harder to achieve using a one-step cooking method. This crumble with oats really is a fantastic dessert and worth giving a try.

Should I thaw frozen fruit before baking?
In this recipe, there isn’t any need to as the fruit is cooked separately first before adding the crumble topping. This helps to warm the fruit through before putting it in the oven and helps to ensure you don’t have a cold crumble.
Top Tip
However, the higher water content created from freezing the fruit makes a little extra juice. If you use a slotted spoon to get the fruit into your serving dish when assembling you can always leave the juice to bubble away. This will reduce and make a lovely fruity sauce for serving

Using sugar replacement and sweeteners
In this recipe, I use a white sweetener which could be either xylitol or erythritol. Both are a 1:1 substitute for sugar and work brilliantly in cakes and desserts
My preference is xylitol and my current favourites are NKD Living Natural Xylitol or Total Sweet Xylitol which is conveniently available in lots of UK supermarkets as well.
If you prefer to use different sweeteners like sucralose or stevia, remember to convert your quantity. Most brands have this information on their websites.
Don’t be afraid to experiment with different sweeteners and the quantities in sweet recipes. It may take a few attempts to find your preference as we all have a different palate.
What you will need to make this frozen fruit crumble with oats
For the oaty crumble topping
- Gluten-free oats
- Oats are naturally gluten-free however it’s in the processing of them that contamination with other cereals may occur.
- Therefore I use GF as my husband has an intolerance however any type of porridge oats can be used.
- Oats are such a magnificent superfood; they are wholegrain, a great carbohydrate source, and full of fibre, essential vitamins, minerals and antioxidants.
- Ground almonds
- These are not only gluten-free but add an extra nutty flavour and are a great no-carb-count option for baking
- High in healthy monounsaturated fats, fibre and protein
- Chopped almonds
- High in healthy monounsaturated fats, fibre and protein.
- Loaded with antioxidants
- Sugar Replacement
- I used Xylitol but you could also use erythritol, stevia or sucralose.
- However, see notes above on sweeteners if using another type
- Butter
- High in saturated fat
- You could also use coconut oil if you prefer
For the stewed frozen fruit:
- Frozen fruit
- Freezing can help to retain the nutrient content of the fruits
- Full of vitamins, minerals and antioxidants.
- Sugar Replacement
- I used Xylitol but you could also use erythritol, stevia or sucralose.
- However, see notes above on sweeteners if using another type.
- Lemon
- Adds a wonderful zesty zing to the dish
- Gives an extra dose of vitamin C

How to make this frozen fruit crumble with oats
This crumble requires minimal effort and is very quick and easy to make which is why I love it so much.
First, you will need to place the frozen fruit into a pan on a low heat with the sugar replacement, lemon juice and zest. stir to combine. Leave it to simmer gently for around 20 minutes, stirring occasionally.
While the fruit is stewing you can make the crumble topping.
Preheat the oven to 180 C fan / 200 C then in a bowl mix the oats, ground almonds, sugar replacement and butter with your hands until you have a breadcrumb-like texture. Now add the chopped almonds and mix in well. Place the crumbs onto a baking sheet and pre-bake in the oven for 15 mins turning them halfway through.
Once baked turn the oven down to, 160 C fan / 180 C.
Now you are ready to assemble. In an ovenproof dish (25×25) add your layer of fruit. However, if there is too much juice from the fruit, use a slotted spoon to transfer it into your ovenproof dish. But remember to keep the juice from the fruit as you can reduce it to make a lovely sauce. Finally, add the crumble mixture on top and cook in your preheated oven for 30 minutes.
Suggestions of other frozen fruit options for this crumble:
There is a vast array of frozen fruit available but here are some other suggestions you could try which make this a great dessert perfect all year round.
- Blackberries
- Cherries – for a wonderful Bakewell tart flavoured pud
- Raspberries
- Blueberries
- Strawberries
- Mixed Berries
- Mango
- Black Forest Fruits
You basically could try and combine from the list above. Experiment and have fun creating the flavour combinations you enjoy.

However, if you prefer a more traditional apple crumble recipe then why not try the apple crumble with oats recipe. Which is also gluten and refined-sugar free.
How to serve your frozen fruit crumble
OK, so I know this all comes down to personal preference but for me without a doubt, it has to be a big dollop of vanilla ice cream. Now the rest of my family would definitely disagree and opt for custard or double cream. So what camp do you stand in?
Oh and by the way, this frozen fruit crumble with oats is also super delicious eaten cold as well!

Diabetes note
This quick and easy frozen fruit crumble is nutrient-rich, and high in fibre and protein. By switching out the traditional wheat flour in the crumble topping makes this dessert kinder on the blood sugar levels, hopefully helping to avoid bigger blood glucose spikes.
Carb Counting
The overall carb count for a serving of this frozen fruit crumble based on the ingredients we would count is:
Oats = 150g – 106.1g of carbs
Frozen fruit – blueberries = 400g – 36.4g of carbs
Frozen fruit – Strawberries = 500g – 30.5g of carbs
Now add all the carbs together – 106.1+36.4 + 30.5 = 173g
Finally divide this by the serving size, 6 – 173/6 = 28.8 g of carb per serving
Please note these are pretty generous serving sizes and that the total carbs of frozen fruit will vary depending on what you choose to use.