Chocolate caramel tart

Name: Chocolate caramel tart
Prep time: 5 h
Cook time: 30 min
Total time: 5 h 30 min
Cuisine: European, British
Ingredients: 82.50 ml hazelnuts, toasted, chopped; Nonstick cooking spray; 187.50 ml plain flour; 42.90 gm cocoa; 1.20 gm fine sea salt; 85g unsalted butter, softened; 107.50 gm caster sugar; 215.00 gm caster sugar; 40.00 gm water; 26.80 gm golden syrup; 40.40 gm cream, at room temperature; 110g unsalted butter; 2.40 gm flaked pink salt, or sea salt; 126.25 gm thickened cream; 80g good quality dark chocolate (70% cacao), chopped