Toffee apples

Method

1. Push a skewer (or clean twig) into the centre of each apple. Put the sugar, vinegar, butter, syrup and 150ml cold water in a heavy-based pan set over a low heat and stir until the sugar has dissolved. Turn the heat to medium-high and boil until the mixture turns a deep golden colour (or until a sugar thermometer or digital probe reaches 140°C). Take the pan off the heat.
2. Using a fork, quickly swirl in some of the red food colouring, if using. Dip the apples into the toffee, turning to coat fully. Transfer to the prepared baking tray, then set aside for at least 30 minutes.