Mix together the rhubarb, golden caster sugar and orange rind and half the juice in a bowl. Spoon the mixture into 4 individual ramekins.
Put the oats, cream, dark muscovado sugar and remaining orange juice in the bowl and mix together. Drop spoonfuls of the oat mixture all over the surface of the rhubarb mixture.
Set the ramekins on a baking sheet and bake in a preheated oven, 180°C (350°F), Gas Mark 4, for 20–25 minutes until the topping is browned. Serve hot.