Preheat oven to 350°F. Grease loaf pan.
In a medium mixing bowl, combine sugar, flour, baking powder and salt. Set aside.
In the fitted bowl of a stand mixer, beat eggs, milk and oil until just combined.
Gradually add dry mixture to wet until just moist. Add diced apple and cinnamon.
Pour mixture into loaf pan, filling to the ⅔ mark to compensate for rise.
Combine cinnamon and sugar topping.
Spoon topping onto each loaf and swirl in with a knife.
Bake 50-60 minutes or until a toothpick comes clean.
Can add vanilla or nuts too.
