In a small mixing bowl, combine the flour, salt and baking powder.
In a large mixing bowl, combine the melted butter, brown sugar and white sugar.
One at a time, mix in the vanilla, then egg, then egg yolk.
Add the dry ingredients to the wet ingredients and combine well.
Mix in the chopped caramels and cashews.
Cover in plastic wrap and chill in the refrigerator for 15-20 minutes, or up to 24 hours.
Remove from the refrigerator and scoop the cookie dough out onto a baking stone.
Sprinkle the additional sea salt over the cookie dough, then place in the oven for 20-25 minutes, or until golden brown.
Cool on the baking stone for 2-3 minutes, then remove from the stone and place on a cooling rack so that the caramel doesn’t stick to the baking stone.