Place half of the sugar in a frying pan or wide sauté pan with the measurement water and the raisins and cinnamon. Bring just to the boil, add the pears and simmer gently, uncovered, for about 5 minutes until the pears are slightly softened.
Melt the butter in a separate frying pan or saucepan. Add the porridge oats and fry gently for 2 minutes. Stir in the remaining sugar and cook over a gentle heat until golden.
Spoon the pears on to serving plates. Stir the hazelnuts and chocolate into the oats mixture. Once the chocolate starts to melt, spoon over the pears. Serve topped with whipped cream or Greek yogurt, if liked.