Preheat the oven to 350F degrees and line a muffin tin with paper liners.
In a large bowl, add oats, flour, sugar, baking powder, baking soda, nutmeg, cinnamon, and salt and stir to combine.
Pour in applesauce, milk, butter, and vanilla extract and stir until fully combined. Place batter into muffin liners.
Bake in preheated oven for for 23-25 minutes or until a toothpick entered in the middle comes out smoothly.
