Preheat the oven to 350°F, grease, and line with parchment paper a 9X5 inch loaf pan. Set aside.
Sift all the dry ingredients together excluding the sugar. set aside.
2 cups All purpose flour, 1 teaspoon Baking soda, ½ teaspoon Cinnamon, ¼ teaspoon Salt
Cream together butter and sugar. beat for 2 minutes.
1 cup Sugar, ½ cup Butter
Add eggs, one at a time. I will look curdled, and it's okay. Add vanilla extract, and mix.
2 Large eggs, 1 tablespoon Vanilla extract
Add the mashed bananas and the apple sauce to the milk and mix well.
½ cup Bananas, ½ cup Apple sauce, unsweetened, ½ cup Milk
Add the sifted dry ingredients to the above mixture and mix with a spatula. DO NOT OVERMIX Add 1 tablespoon milk to the Nutella and microwave for 15 seconds, until Nutella is loosened up.
1 tablespoon Milk, ½ cup Nutella
Pour half of the cake batter into the pan, and add half of the Nutella mixture with a small spoon. With a tip of a knife or stick make swirls into the Nutella and the cake batter.
Add the second half of the batter to the pan and add the remaining Nutella and swirl it around.
Bake for 40-45 minutes or until an insert comes out clean. Let cool in the pan for 10 minutes and then transfer to a cooling rack by lifting the paper overhang.