Step 1

Preheat oven to 180°C. Combine the rhubarb, apple and water in a large saucepan over medium heat. Bring to a simmer. Reduce heat to low and cook, stirring occasionally, for 10 minutes or until the rhubarb softens.

Step 2

Add the caster sugar to the pan and stir until the sugar dissolves. Pour the rhubarb mixture into a 1.5L (6-cup) capacity ovenproof dish.

Step 3

Combine the biscuit, ginger, butter and brown sugar in a medium bowl.

Step 4

Sprinkle the biscuit mixture over the rhubarb. Bake in oven for 10 minutes or until the crumble is crisp and the rhubarb mixture bubbles. Serve immediately with ice-cream.