Heat oven to 325 degrees. Spray two loaf pans (9-inch x 5-inch) with non-stick cooking spray.

In a large bowl, add granulated sugar, oil, and eggs. Whisk together until combined and smooth. Add in the applesauce and buttermilk. Mix together until combined.

Add in the flour, cinnamon, baking soda, baking powder, and salt. Stir together with a spatula or spoon just until combined and no flour streaks remain.

Divide batter evenly between the two prepared pans. Each loaf pan should be about halfway filled with batter.

In a bowl, combine the quick oats, brown sugar, cinnamon, and flour for the streusel topping together. Microwave the butter for about 15 seconds. You want it to be softened and partial melted. Then mix into the streusel mixture until all of the mixture is wet. Sprinkle half of the mixture over each of the loaf pans.

Bake at 350 degrees for 60 minutes or until a toothpick inserted in the center comes out clean. Makes 2 loaves.