Preheat your oven to 350°F (175°C).

In a bowl, whisk together the flour, baking powder, and salt.

In a separate bowl, beat together the softened butter, granulated sugar, and brown sugar until creamy.

Add the egg and vanilla extract to the butter mixture, mixing until combined.

Gradually mix the dry ingredients into the wet ingredients until just combined.

In another bowl, toss the diced apples with the cinnamon, nutmeg, and tablespoon of flour.

Fold the apple mixture gently into the dough until evenly distributed.

Using a cookie scoop or spoon, drop rounded tablespoons of dough onto a parchment-lined baking sheet.

Bake in the preheated oven for 12-15 minutes, or until lightly golden around the edges.

Let the cookies cool on the sheet for 5 minutes before transferring them to a wire rack to cool completely.