In a medium bowl, whisk together the flour, baking soda, cinnamon, nutmeg and salt.
Put the apple sauce and sugar in another large bowl. Add the egg, mixing well to incorporate. Stir in the oil and vanilla, mixing well.
Stir in the flour mixture until just combined.
Set batter aside to rest for 30 minutes.
Fold in the chopped apples.
Spray an 8x4-inch loaf pan with nonstick spray, and pour in your batter. Decorate with thin-sliced apples (if desired), and sprinkle the top with cinnamon sugar.
Bake for 45 minutes to an hour, or until a toothpick or cake tester comes out clean. I usually check and rotate the pans after the first 30 minutes.
Notes
*If you want to lower the amount of refined sugar in this recipe, replace the sugar with raw coconut sugar or maple sugar. The bread will have a slightly richer, molasses-like hint to it.