Preheat the oven to 350°F. Grease or line a 9×5” loaf pan.
In a small saucepan, simmer 3/4 cup apple cider until reduced to 1/3 cup. Let cool.
In a large bowl, mix mashed bananas, applesauce, reduced cider, brown sugar, eggs, and vanilla.
Stir in flour, baking soda, salt, and spices until just combined.
Fold in diced apple.
Pour into the prepared pan and smooth the top.
Bake for 55–65 minutes or until a toothpick comes out mostly clean. Top with melted butter and cinnamon sugar. Use 1/2 to 1 tbsp depending on your preference. The more cinnamon sugar, the more it feels like a donut!