Source: Adapted from Allrecipes.com
1/3 cup white sugar
2 teaspoons ground cinnamon
2 cups all-purpose flour
1 tablespoon baking powder
1/2 teaspoon salt
1 cup white sugar
1 egg, beaten
1 cup milk
1/3 cup applesauce
1 teaspoon vanilla
Preheat oven to 350 degrees. Lightly grease a 9x5-inch loaf pan. In a small bowl, mix together 1/3 cup sugar and 2 teaspoons cinnamon; set aside.
In a large bowl combine flour, baking powder, salt and remaining 1 cup sugar. Combine egg, milk and applesauce; add to flour mixture. Stir until just moistened.
Pour half of the batter into pan. Sprinkle with half the reserved cinnamon/sugar mixture. Repeat with remaining batter and cinnamon/sugar mixture. Draw a knife through the batter to marble.
Bake in a pre-heated oven for 45-50 minutes, or until a toothpick inserted into the center comes of out clean. Let cool in pan for 10 minutes before removing to a wire rack to cool completely.