Preheat your oven to 350°F (175°C) and prepare a muffin tin with paper liners or cooking spray.
In a large bowl, whisk together the flour, baking powder, baking soda, cinnamon, nutmeg, and salt.
In another bowl, combine the granulated sugar, brown sugar, melted butter, eggs, and vanilla extract, mixing until well incorporated.
Add the wet mixture to the dry ingredients, stirring gently until just combined; be careful not to overmix.
Fold in the chopped apples, ensuring they are evenly distributed throughout the batter.
Spoon the batter into the prepared muffin tin, filling each cavity about two-thirds full.
Bake for 18-22 minutes or until a toothpick inserted into the center comes out clean.
Allow the muffins to cool in the tin for 5 minutes, then transfer them to a wire rack to cool completely.