Steps

1. Set a 15 mm ganache frame on parchment paper and set a barrier to leave a 10 cm by 33.5 cm space. Set a weight on the barrier to keep it in place when the caramel is poured in.
2. Combine sugar and water and set on heat to dissolve the sugar and boil.
3. Bring cream to a light simmer and keep warm.
4. Combine evaporated milk and glucose and set on heat until glucose dissolves, then keep warm.
5. Continue to cook sugar until it caramelizes to light amber colour, 375 °F.
6. Immediately but slowly stir in second measure of water to cool to 250 °F, then stir in cream, then evaporated milk mixture.
7. Cook to 230 °F, stirring frequently.
8. Add butter and continue to cook to 239 °F, stirring constantly.
9. Cut heat. Sift salt over caramel and stir in well until even distributed.
10. Let cool until bubbling stops and caramel cools below 200 °F. Stir in vanilla extract.
11. Immediately transfer to frame. Spread evenly to edges, then cover with a piece of parchment paper and smooth.
12. Cool several hours, then cut into squares and wrap each in parchment paper.