Add the sugar to a medium heavy-bottomed saucepan and heat over medium-low heat, stirring occasionally until the sugar has melted and turns golden brown, about 15 minutes. Be patient while the sugar melts. It will clump before it melts then it caramelizes quickly, so keep an eye on it so the sugar doesn’t burn.

Remove the pot from heat and stir in the butter (it will bubble).

Slowly stir in the cream, stirring constantly until completely combined. Stir in the soy sauce. Let cool completely and use right away or add to an airtight container and store refrigerated until ready to use.

In the bowl of a stand mixer fitted with a paddle attachment, beat the butter, flour, sugar, vanilla and kosher salt until the crumbs form and the mixture just comes together, about 1 minute.

Add ½ cup (87g) of the caramel sauce and mix again until just combined but the caramel is still visible, being careful not to over-mix.

Heat oven to 350ºF (180ºC). Line an 8” x 8” (20cm x 20cm) pan with buttered parchment paper. Press the cookie dough evenly into the pan (if the dough is too sticky, top with another piece of parchment paper or coat a spatula in flour).

Bake until the edges are golden brown, about 25 to 30 minutes.

Let cool for 10 minutes then drizzle with 2 tablespoons (56g) of the remaining caramel. Cut into bars and serve.