Rhubarb crumble

Rhubarb crumble

45 min
Rhubarb signals the beginning of summer, and there is probably no better way to enjoy rhubarb than in a simple yet irresistible crumble with warming cinnamon. A guaranteed after-dinner success!


  • Set the oven to 225°.
  • Cut the rhubarb into slices. Mix the rhubarb, potato starch, cinnamon and caster sugar in an ovenproof dish.
  • For the dough, mix the rolled oats, flour and caster sugar in a bowl. Add the butter, cut into pieces and work into a crumbly dough.
  • Crumble the dough over the rhubarb.
  • Bake in the middle of the oven for about 20 minutes.
  • Serve with custard and enjoy!

Rhubarb crumble

Can you make the crumble without oatmeal?
Not everyone enjoys the taste and texture of oats in their crumble. It's perfectly fine to swap the oats for flour in this recipe. If you do, you may want to adjust the amount of butter just a bit, leaving out perhaps 25 g. If you're looking to make a gluten-free crumble, you can easily substitute both the wheat flour and the oats with any gluten-free flour alternative. You can also try swapping part of your gluten-free all-purpose flour with almond flour or other nut flours.
Why use potato starch in rhubarb pie?
Crumble is all about texture. You want the contrast between crisp, crunchy crumble topping and soft, cooked fruit. But you don't want the fruit to be too runny, juicy, or even watery. This is where potato starch enters the picture (you can also use corn starch). Potato starch is commonly used as a thickener in soups, sauces and pies. By adding the starch to your chopped rhubarb, you ensure that the juices released during cooking are captured and transformed into a creamy, flavourful sauce.
How long can I keep rhubarb in the fridge?
Like with most fruit pies, any leftovers from your rhubarb crumble should be covered well and stored in the fridge. The crumble will keep for about 4 days like this – but always check that it looks and smells ok before digging in. It can be tempting to enjoy crumble straight from the fridge with a dollop of cream or custard. However, we do recommend heating it in the microwave or oven first to fully unlock its flavours.
Can you freeze rhubarb crumble?
Want to save your crumble for a later date? No problem. Simply place it in a freeze-safe container and pop it in the freezer. Your crumble can stay in the freezer for about three months. Defrost it overnight in the fridge and reheat before serving. As always, it's best to check that the crumble looks and smells good before eating it.
Why is my rhubarb pie runny?
Rhubarb has a naturally high water content and can quickly lead to an overly runny pie. Our top tip is to add the sugar to the diced rhubarb and leave it to soften for 30 minutes. This process will release the fruit's juices and help prevent a runny, soggy pie. The potato starch in this recipe also acts as a thickener, bringing you all the closer to the perfect slice of rhubarb pie, every time.


500 g
Potato starch
½ tbsp
Ground cinnamon
1 tsp
Caster sugar
4 tbsp
Rolled oats
53 g
90 g
Caster sugar
45 g
125 g
Vanilla cream
500 ml

A classic old-fashioned rhubarb crumble

Spring and early summer – that's the season to relish the humble rhubarb. What better way to enjoy the tart flavour of rhubarb than in a crowd-pleasing, easy-to-make crumble? As an afternoon treat, served with whipped cream, custard, or vanilla ice cream, this crumble is sure to bring back sweet memories of summers past. Sugar and cinnamon help bring out the rhubarb's mild yet enticing taste, while the crumble adds a buttery crisp texture. The trick is to maximise the contrast in flavour and texture – letting the crispy crumble develop deep colour and flavour while the rhubarb softens and cooks through completely.

Learn how to cut rhubarb

If you are lucky enough to have harvested your own rhubarb, the first step is to remove the big leafy end. The leaf is actually poisonous, so don't worry about wasting it. Rinse the rhubarb under running water, then cut off the bottom end and discard it. Now, you have the choice of removing the outer 'skin' of the stalk: cutting a small slit at one end just below the surface and pulling the skin off, then repeating until the rhubarb is peeled. This step is not essential, though, as cooking will soften the rhubarb's fibres. Finally, dice the rhubarb by cutting crosswise and working your way along the stalk.

How to make perfect crumble

A first step to making the perfect crumble topping is to make sure that the ingredients are properly combined – you don't want any dry, unbuttered oats in there. This is best achieved by using your hands to squeeze and rub the butter together with the grains, flour and sugar. Using a food processor, you risk mincing the crumble too finely, ending up with a solid biscuit instead of a textured crumble on top of your rhubarb. Some recommend freezing the crumble topping for a bit before spreading it, to retain the crumbly texture. You can also try adding chopped almonds or hazelnuts to your crumble topping for extra crunch and flavour.