Preheat your oven to 375°F (190°C). Grease a muffin tin or line with paper liners.
In a large bowl, whisk together the flour, sugar, baking powder, baking soda, cinnamon, and salt.
In another bowl, beat the eggs, then add the oil, milk, and vanilla extract. Mix well.
Pour the wet ingredients into the dry ingredients and stir until just combined. Do not overmix.
Fold in the chopped apples.
Divide the batter evenly among the muffin cups, filling each about ⅔ full.
Bake for 20 minutes or until a toothpick inserted into the center of a muffin comes out clean.
Allow the muffins to cool in the tin for 5 minutes, then transfer to a wire rack to cool completely.