Preheat the oven to 180˚C.
Sift the flour into a bowl and add the caster sugar, butter, flaked almonds.
Combine together until the mixture resembles breadcrumbs.
Place the crumble mixture on a baking tray and place in a preheated the oven to bake for 5 minutes until just toasted. Remove from the oven and set aside.
Meanwhile, place the rhubarb into a saucepan with the orange juice and the sugar. Simmer for 4 – 5 minutes until softened. Pour the softened rhubarb into a baking dish and top with the crumble mixture.
Bake in a preheated oven for 15 minutes until hot and bubbly.
Serve with whipped cream.