(click on the text to highlight each stage):

1. You will need a 24cm round tin
2. Preheat the oven to 180°C, Gas Mark 4
3. Melt the butter in a 24cm ovenproof frying pan over a medium heat. Stir in half the sugar, and cook for about 5 minutes. Remove from the oven and add the rhubarb and ginger.
4. If you do not have an oven proof frying pan pour the rhubarb mix into a 24cm round tin.
5. Mix together the flour, baking powder, bicarbonate of soda and salt and orange zest.
6. Whisk the remaining sugar with the buttermilk, eggs and oil. Add the flour mix, and mix well. Pour over the rhubarb and smooth the surface.
7. Bake for 30 minutes or until the cake springs back when pressed in the centre. Cool then invert on a serving plate. Serve warm with custard or cream.