Start by adding the apple cider to a saucepan over medium heat. Bring it to a boil before reducing it to a simmer. Cook until it's reduced by half—this should take about 20-30 minutes. Set aside to cool while you preheat your oven.
Preheat your oven to 350 degrees Fahrenheit. Grease or butter a 9x5 loaf pan.
In a mixing bowl, add the room temperature butter and brown sugar. Beat them together until light and fluffy.
Beat in one large egg along with one teaspoon of vanilla extract until well combined.
Mix in all the dry ingredients along with the cooled reduced apple cider. Stir until just combined; do not overmix.
Pour your batter into the prepared loaf pan and bake for about 50 minutes or until a tester comes out clean.
Let your bread cool in the pan for about 15 minutes before transferring it onto a cooling rack.
Brush the top and sides of your warm bread generously with melted butter.
In a small bowl, combine sugar and cinnamon. Sprinkle this mixture over the top and sides of your loaf.
Let the bread cool completely for about one hour before slicing into it.