Preheat oven to 400 degrees F.
In a large bowl, mix the flour, baking soda, baking powder, salt, cinnamon, and nutmeg. Mix well.
In a separate bowl, add the starter, milk, oil, maple syrup or honey, vanilla extract, egg, and grated apple.
Mix well and pour into the dry ingredients.
Mix until combined. Optionally, add in the millet.
Prepare a 12 cup muffin tin by adding some oil or muffin liners.
Scoop the batter evenly into the muffin tin.
Bake for 15-17 minutes or until a toothpick comes out clean.