In a small skillet over medium heat, combine the diced firm tart apples, dark brown sugar, and cinnamon. Stir frequently for about 5 minutes until the apples soften slightly but retain their shape. Remove the skillet from heat and allow the apple mixture to cool while you prepare the cookie dough.

In a large mixing bowl, blend the softened unsalted butter, dark brown sugar, and granulated sugar using a hand mixer on medium speed for 1 to 2 minutes until the mixture appears pale and fluffy.

Add the large egg to the butter and sugar mixture, beating until fully incorporated, which should take about 30 seconds.

In a separate bowl, whisk together the all-purpose flour, baking soda, salt, and cinnamon. Gradually fold these dry ingredients into the butter mixture until just combined.

Gently fold half of the cooled apple mixture into the dough, then the remaining apples, ensuring to avoid adding excess liquid.

If the cookie dough feels too loose or sticky, refrigerate it for about 20 minutes to firm it up.

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

Using a cookie scoop or spoon, drop mounds of dough onto the prepared baking sheets, spacing them about 2 inches apart. Bake for 12 to 16 minutes, until the tops are golden.

Allow the cookies to cool on the baking sheet for about 2 minutes, then transfer them to a wire rack to cool completely.

Once cool, drizzle with salted caramel sauce and enjoy!