Step 1: Preheat the oven to 350°F (175°C). Grease a 15-cup cupcake or mini-muffin pan and set it aside.

Step 2: In a large bowl, mix the melted butter and 1 cup of brown sugar together. Stir in the egg and vanilla extract until well combined.

Step 3: In a separate small bowl, whisk together the flour, baking powder, 1/2 tsp salt, and 1/2 tsp ground cinnamon.

Step 4: Gradually add the dry ingredient mixture to the wet ingredients, mixing until a soft dough forms.

Step 5: Roll the dough into 15 equal-sized balls. Press each ball into a cup of the prepared pan, pressing the center down to create a cup shape.

Step 6: Bake for 11-13 minutes, or until the edges are lightly browned. Allow the cookie cups to cool completely in the pan.

Step 7: While the cookies cool, prepare the filling. In a medium saucepan, combine the diced apples, 1 tsp ground cinnamon, nutmeg, 2 tbsp brown sugar, and 2 tbsp unsalted butter.

Step 8: Cook the apple mixture over medium heat, stirring occasionally, for 5-10 minutes, depending on how soft you want the apples. Remove from heat and let it cool slightly.

Step 9: To assemble, add a small spoonful of salted caramel sauce into the bottom of each cooled cookie cup.

Step 10: Spoon the apple filling on top of the caramel layer.

Step 11: Finish by drizzling more salted caramel sauce over the top of the apple filling before serving.