Preheat the oven to 190ºC.
Combine all ingredients in a heavy, ovenproof dish and mix well.
Bake uncovered, stirring often, for 30-45 minutes until the pears are golden and starting to caramelise. Allow to cool before using. These pears can be refrigerated in an airtight container for a few days.
For the pudding:.
Preheat the oven to 160ºC. Grease a 2-litre pudding bowl or similar dish with the softened butter.
Press down a layer of croissant or brioche, then a layer of roasted pears, a sprinkling of cinnamon followed by a layer of chocolate.
Repeat until all ingredients are used up, ending with a croissant layer and a little chocolate on the very top.
Whisk eggs, cream and caster sugar then strain. Pour this mixture over the pudding and press down on top of the croissants or brioches so they all absorb some of the custard. Allow to sit for half an hour. Sprinkle with brown sugar and bake for 45-60 minutes until the liquid has been absorbed. Leave the pudding to cool for 20 minutes.
Serve with lightly whipped cream or a large dollop of mascarpone.