Preheat the oven to 350°F (180°C). Grease an 8x8-inch (20x20 cm) baking pan with butter and line with parchment paper, leaving a few inches of overhang on all sides.

In a medium bowl, combine the flour, sugar, and salt. 

Add the cold butter cubes and cut it into the flour mixture using a pastry cutter. Cut until the butter forms pea sized chunks. The dough will be dry and crumbly.

Tip the dough into the baking pan and firmly pack it in using the bottom of a glass or measuring cup.*

Bake for 22-25 minutes or until the edges are lightly golden brown. Set aside to cool while you make the caramel.

In a large saucepan over medium heat, melt the sweetened condensed milk, brown sugar, and butter while stirring frequently (we recommend using a silicone spatula).

Once melted, whisk in the miso paste until dissolved.

Stir constantly, scraping the bottom and sides of the pan to prevent any caramel from burning.

As it cooks, it will bubble and thicken. Continue stirring until it reaches a temperature of 225°F (107°C).

Pour the caramel over the shortbread crust and spread it into an even layer using a small offset spatula.

Chill in the fridge for 1 hour to set.

In a bowl placed over a pot of simmering water, stir the chocolate and cream together until melted.* The bowl should not be touching the water.

Pour it over the caramel layer and spread it evenly with a small offset spatula.

Generously sprinkle the top with flaky sea salt.

Chill in the fridge for 2 hours then remove the shortbread from the pan and slice into pieces. If you like your chocolate to have more bite, leave it in the fridge for a couple more hours.