Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.

Whisk together the all-purpose flour, baking soda, ground cinnamon, ground nutmeg (if using), and salt in a large mixing bowl.

Beat the softened unsalted butter and brown sugar together until light and fluffy, about 3 to 5 minutes.

Add the large eggs, apple cider, and vanilla extract to the creamed mixture, mixing on low speed until well combined.

Fold in the dry mixture into the wet ingredients until just combined, with slight streaks of flour remaining.

Drop rounded balls of dough onto the prepared baking sheets, leaving about 2 inches of space between each scoop.

Bake for 12 to 15 minutes until golden edges form and centers remain soft; cool for a few minutes.

Melt butter in a saucepan, stir in brown sugar and heavy cream, bring to a boil and simmer for 3 to 5 minutes to thicken.

Once cookies are cooled, spread warm caramel filling on the flat side of one cookie and sandwich with another.