Add the hard cider to a medium saucepan. Bring to a boil and then simmer until the liquid has been reduced to 1¼ cups (this took me 30 minutes). Let cider cool completely.
Preheat your oven to 350°F.
In a large bowl combine the cake mix, eggs, vegetable oil, and 1 cup of reduced hard cider. Mix together until well incorporated.
Line two 12-cup muffin tins with paper liners. Pour the batter into the paper liners, filling each liner about ⅔ full.
Bake for 18-20 minutes, until a toothpick inserted in the center of a cupcake comes out clean. Let cool completely.
Make the frosting: Add the room temperature butter to a large bowl and beat until light and fluffy. Add in the cinnamon, vanilla extract and remaining ¼ cup hard apple cider and beat until combined. Slowly add in the powdered sugar until it is fully incorporated.
Transfer the frosting to a piping bag or zip-top bag. Pipe the frosting onto the cupcakes.
Enjoy!