Preheat the oven to 425 degrees. Pour the condensed milk into a pie plate and cover it tightly with foil. Put the pie plate in a big roasting pan, and fill the pan halfway up the pie plate with hot water. Bake for 1 to 1 ¼ hours, adding more water if necessary. Let cool, then whisk until smooth. You will have perfect caramel sauce.
For the cookies:
Preheat the oven at 350 degrees.
Cream the butter and sugar in a mixer. Add the vanilla. Mix the salt with the flour, then add the dry ingredients a little at a time and mix until the dough comes together. Roll the dough into a log, wrap in plastic wrap and refrigerate 30 minutes. Slice ¼ “ thick cookies. Bake for 20-24 minutes, transfer to a wire rack to cool. When cooled, top each cookie with about 1 teaspoon of the caramel. Drizzle with melted chocolate & sprinkle with sea salt.