Put the cider in a saucepan, bring to a simmer and cook until reduced to 3/4 cup, about 20 minutes. Remove 1/4 cup of the reduced cider and reserve. Add 3 tablespoons of the sugar to the saucepan with the remaining 1/2 cup cider. Heat to combine and set aside.
Preheat the oven to 350 degrees F. Line a 12-cup muffin tin with 9 liners and spray with nonstick cooking spray.
Using a stand mixer fitted with a paddle attachment, cream the butter and remaining 5 tablespoons sugar until fluffy, 2 to 3 minutes. Add the eggs one a time, stirring between each addition, followed by the vanilla extract. Beat until smooth.
Combine the flour, baking soda and salt in a medium bowl. Add half the flour mixture to the creamed butter, then add in the apple butter, sour cream and reserved 1/4 cup hard cider and combine again. Add the remaining flour and beat until just combined. Divide the batter among the 9 liners and cook until a toothpick comes out clean, about 20 minutes.
While the cupcakes are still warm, brush the tops with the remaining 1/2 cup hard cider-sugar mixture.