Line a baking tray with parchment paper. In a small bowl, whisk together flour and salt.

In the bowl of an electric mixer, beat together butter and sugar until light and fluffy. Beat in egg and vanilla, then add flour mixture and mix until completely combined.

Scoop out dough and roll into 2.5-cm balls. Place balls a few centimetres apart on baking tray and use a teaspoon measure or your thumb to press a small divot into each ball. Freeze 30 minutes and preheat oven to 180ºC (160ºC fan).

Remove cookies from freezer and bake until golden, 13 to 15 minutes. Let cool.

Fill each cooled cookie cup with 1 teaspoon caramel and lightly drizzle with melted chocolate. Refrigerate, 15 minutes, then serve.