Top and tail the rhubarb and remove the stringy skin. Cut the sticks into 2.5cm (1 inch) lengths, put them in a large ovenproof dish and sprinkle with the caster sugar. Add the stem ginger and stem ginger syrup.
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Step 2
To make the crumble, sift the flour into a bowl. Add the butter and rub in with your fingertips until the mixture resembles fine breadcrumbs. Stir in the caster sugar.
3
Step 3
Cover the rhubarb with the crumble and press it down lightly. Sprinkle the surface with the demerara sugar.
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Step 4
Bake in a preheated oven, 190°C (375°F), Gas Mark 5, for 40 minutes until golden brown. Serve with hot custard.