Place the apple cider in a small sauce pan over medium-low heat. Cook it for 20-25 minutes, or until the cider has reduced by half.
Preheat your oven to 350F. Line a muffin pan with baking cups or spray it with non-stick baking spray. Set aside.
In a large bowl, combine the apple cider, melted butter, and eggs. Whisk until they are fully combined.
Next, add in the flour, sugar, salt, baking powder, cinnamon, and cardamom. Whisk just until no large lumps of flour remain. Note: It is okay for small lumps to remain. Over-mixing will result in dense muffins.
Divide the batter evenly between the 12 muffins— the batter should fill the each hole about 3/4 of the way.