Preheat your oven to 350℉ and prepare your muffin baking pan with paper liners. Consider spraying the inside of the liners with cooking oil to help remove the muffins after baking.
Grab a large mixing bowl and add flour, granulated sugar, brown sugar, baking powder, baking soda, salt, cinnamon, and nutmeg. Whisk together to combine.
In another mixing bowl, add in the stick of melted butter, milk, vanilla extract, and eggs until well combined. You can use a handheld or stand mixer to mix.
Mix in the dry ingredients to the wet ingredients. Be careful to not overmix.
Slowly mix in the chopped apples. Stop mixing when they are evenly distributed.
Grab the prepared muffin baking pan and fill the muffin cups ⅔-¾ of the way full with the muffin batter.
Bake at 350℉ for 20-25 minutes or until a toothpick inserted into the center of one of the muffins comes out clean.
Carefully remove the muffins from the oven and allow to cool for 5-10 minutes. Now they are ready to enjoy!