In a mixing bowl, combine 1 cup of granulated sugar with 2 teaspoons of apple pie spice, stirring until well blended. Set aside.

In another bowl, whisk together 2 1/2 cups of all-purpose flour, 2 teaspoons apple pie spice, 1 teaspoon baking powder, and 1/4 teaspoon salt. Set aside.

In a large mixing bowl, beat 1 cup of softened unsalted butter and 1 cup plus 1/3 cup of granulated sugar until creamy. Add the egg and vanilla extract, mixing well. Gradually add the dry ingredients until just combined.

Scoop about 1 inch of dough, roll into balls, and coat in the spiced sugar mixture. Place on a baking sheet lined with parchment paper and make a thumb indentation. Chill for 2-3 hours.

Preheat oven to 350°F (180°C), then bake the chilled cookie balls for about 12 minutes.

After baking, re-indent the centers and fill with salted caramel. Return to the oven for 1-2 minutes.

Cool on baking sheets for about 5 minutes before transferring to a wire rack.