Make the tart crust

• Whisk the flour and salt in a bowl, then rub in the cold butter until crumbly.
• Add the sugar, cream and egg yolk and bring the dough together without overworking.
• Flatten into a disc, wrap and chill until firm.

Blind bake the crust

• Roll the dough out and line the tart pan, pressing it into the edges.
• Prick the base and chill again briefly.
• Bake at 180 °C until golden, then let it cool completely.

Cook the salted caramel

• Melt the superfine sugar in a saucepan over medium heat until a deep amber caramel forms.
• Add the diced salted butter and stir until melted.
• Pour in the warm heavy cream and stir until smooth, then let cool slightly.

Fill the tart

• Pour the salted caramel into the cooled crust.
• Smooth the surface and chill until set.

Make the chocolate ganache

• Heat the heavy cream until just simmering and pour it over the chopped chocolate.
• Let stand, then stir until glossy and smooth.

Glaze and finish

• Pour the ganache over the set caramel and spread evenly.
• Chill until the glaze is set, then slice and serve.