4tbspcaster sugaradjust to taste depending on how tart your rhubarb is
1tspground cinnamon
For the crumble topping:
225gplain flour
110gcold buttercubed
110gdemerara sugar
Instructions
Set your oven to 180°C (160°C fan) / 350°F / Gas 4.
In a baking dish (roughly 20x20cm or similar), toss the rhubarb with the 4 tbsp caster sugar. Sprinkle the 1 tsp of ground cinnamon over the top followed by 2 tbsp of water.
In a mixing bowl, rub the flour and butter together with your fingertips until it looks like breadcrumbs (or pulse in a food processor).
Stir in the brown sugar.
Scatter the crumble topping evenly over the rhubarb mixture. Don’t press it down – you want those lovely crumbly bits to stay light and crisp.
Bake in the oven for 35–40 minutes, until the topping is golden brown and the rhubarb is bubbling up around the edges
Notes
*I used 800g of rhubarb. You don't have to use this exact amount, for example, if you only have 700g of rhubarb it's fine to just use that.