Mix the dry ingredients in one bowl and set aside.
Whisk wet ingredients together.
Add dry ingredients to wet and mix well, working out any lumps.
Pour half of the batter into the loaf pan (or small loaf pans).
Sprinkle half of cinnamon sugar mixture on batter. Use a knife to swirl the cinnamon sugar mixture into the batter.
Spread remaining batter on top and sprinkle remaining cinnamon sugar mixture on top.
Bake at 350 for 55 minutes to an hour (or 25 minutes if using small loaf pans).