Submerge the apples in a pan of boiling water for 30 seconds. This will remove the wax and help the caramel to stick to the apple. Remove with a slotted spoon, then wipe the skins with kitchen paper.
Remove the stalks and pierce each apple with a lolly stick or wooden skewer. Press the stick far enough in so it won’t come out, but be careful not to go the whole way through the apple.
Line a baking tray with non-stick baking paper. To make the caramel, put the sugar into a large saucepan with the syrup, butter, vanilla and Cornish Sea Salt Flakes. Heat slowly over a medium heat for around 8 minutes, or until the sugar has dissolved.
Increase the heat, bringing the mixture to a rolling boil. Add a sugar thermometer and boil for around 8 minutes or until the thermometer reaches 140°C ‘hard crack’ stage. Be careful not to touch the caramel. If you don’t have a thermometer you can test it by spooning a little into a bowl of cold water. It should harden instantly and when removed be brittle and easy to crack.
Remove the caramel from the heat. Submerge each apple into the caramel, twist using the stick making sure all but the very top is covered. Sprinkle with a good pinch of Cornish Sea Salt Flakes and place on your baking tray. Continue until all the apples are covered. Allow the coated apples to set for 1 hour before serving.
Cornish Sea Salt Flakes also available at Sainsbury's, Waitrose, Tesco & Coop.