Rhubarb Madeleines

• 500 g (1 lb 2 oz) rhubarb
• 1

Put the rhubarb, orange zest and juice, raw sugar and ginger in a bowl. Cover tightly with plastic wrap to seal and leave overnight in the refrigerator to marinate. Remove the rhubarb, discard the marinating liquid, dice the rhubarb into 2 cm (¾