Preheat the oven to 350 degrees Fahrenheit.
In a mixing bowl, combine the whole wheat flour, all-purpose flour, oats, baking powder, baking soda, cinnamon, and salt. Stir to combine.
In a separate bowl, combine the pumpkin, maple syrup, oil, egg, vanilla, and milk. Mix well.
Add the wet ingredients to the dry ingredients and mix until combined. Add apples to the mixture and stir.
Line a muffin tin with muffin papers or spray each individual muffin cup with cooking spray. Fill each muffin cup to the top.
Bake in the oven for 13-15 minutes. Set aside to cool.