Have an oven proof frying pan ready for use approx 22cm/9" size.
Peel and core the pears and slice in half.
Put the sugar and 50ml/2fl oz water and the cinnamon into the frying pan and heat gently until everything has dissolved.
Bring up to the boil and let it simmer for 5 minutes to create a golden mix.
Remove from heat and stir in the butter and salt.
Arrange the pear halves in the pan with the domed sides downwards and the cut sides facing up.
Cook for 5 minutes and then leave to cool completely.
Preheat oven to 200C/180F/Gas 6
Roll out the puff pastry until it's very thin, about 2mm and a bit bigger than the pan you are using. Carefully lift using your rolling pin to help and lay it over the pears in the pan. Tuck in the edges all around the pears.
Bake for approximately 30 minutes until golden.
Let it cool before inverting on to a serving plate.
Serve with ice cream or cream.