Pour 2 cups of fresh apple cider into a saucepan and bring it to a vigorous boil. Simmer until reduced to about 1/4 cup, around 15-20 minutes.

In a medium pot, combine granulated sugar and a few drops of lemon juice. Cook until deep amber, about 8-10 minutes. Stir in room-temperature heavy cream, then add butter, flaky sea salt, boiled cider, and vanilla extract.

Preheat oven to 350°F (175°C) and toast the raw pecans until golden, about 8-10 minutes. Grind them in a food processor until finely ground.

Combine ground pecans, flour, powdered sugar, and fine sea salt in a mixing bowl. Add room-temperature butter and cooled boiled cider and mix until cohesive. Chill the dough for at least 2 hours.

After chilling, preheat the oven again to 350°F (175°C) and slice the dough into 1/2 inch rounds. Bake for about 10 minutes and cool on wire racks.

Once cool, drizzle the salted cider caramel over each cookie and sprinkle with flaky sea salt and toasted pecans if desired.