Cut the butter into cubes and leave at room temperature to soften.
Line the square tin with parchment paper.
Lift the Cooking Chef head and fit the heat shield.
Fit the Creaming Beater to the machine.
Attach the Cooking Chef bowl to the machine.
Add Ingredients 1 (butter, sugar, syrup, cream) into the Cooking Chef bowl, fit the splash guard.
Cook at 105°C, on speed Stir 1 for 6 minutes until the sugar has dissolved.
Cook at 150°C, on speed Stir 4 for 25 minutes.
Cook at 167°C, on speed Stir 4 for 5 minutes.
Add Ingredients 2 (vanilla extract, salt) to the bowl.
Mix on speed 1 for 10 minutes.
Carefully pour contents of the Cooking Chef bowl into the lined tin.
Chill in the fridge until set.
Cut into squares.
Serve.
Sprinkle with extra sea salt.