Put the flour into a large mixing bowl and use your fingers to rub in the unsalted butter intil it looks like bread crumbs. Stir in 4 tablespoons of the demerara sugar and chopped hazelnuts and then cook in the preheated oven for 5 to 10 minutes
Spoon the Golden Syrup into a saucepan while heating over a low heat. Now add the sugar, 1 tablespoon of the unsalted butter, the vanilla extract and all the cream. Gently bring to the boil and then let simmer for 3 minutes while stiring constantly. Take this off the heat and put to one side
PEAR AND FILLING:
Use the unslated butter thats left and place in a frying pan and melt over a low heat. While melting peel and chop the pears. Add them to the pan and cook for 3 minutes while stirring. Stir in the pre made toffee and carry on cooking at a low heat for a further 3 minutes.
Take the Pear and toffee mix a put in an oven proof dish. Place the crumble topping on top of the mixure making sure it fully covers the pear and toffee mix. Bake all this for 25 to 30 minutes in the oven until the crumble has a brown crunchy topping.