Preheat the oven to 180°C, fan 160°C, gas 4.
Cut a thin slice off the base of each apple so they stand up easily. Scoop out the core and score through the skin around the centre ofthe apple to stop the skin bursting.
Stand each apple on a piece of foil in a baking dish and push sultanas into each cavity. Press a knob of butter on topof each, then drizzle over the golden syrup.
For the toffee sauce, mix together the cream and vanilla, then pour over the apples. Loosely enclose the apples in the foil and bake for 35 mins until the apples are soft throughout. Serve the apples with the toffee sauce spooned over the top.