In a small saucepan, bring 1 cup of apple cider to a gentle simmer and reduce to ½ cup.

In a large bowl, whisk together melted butter, granulated sugar, brown sugar, eggs, sour cream, vanilla, and reduced cider.

In another bowl, mix together flour, baking powder, baking soda, cinnamon, nutmeg, and salt.

Gently fold the dry ingredients into the wet mixture until just combined, avoiding overmixing.

Grease a 9×5-inch loaf pan and pour in the batter, smoothing the top.

Bake in a preheated oven at 350°F (175°C) for 45-50 minutes; check doneness with a toothpick.

Let the bread cool in the pan for 10 minutes before transferring to a wire rack.

Brush the top and sides with melted butter, then sprinkle with the sugar-cinnamon mixture.