Preheat the oven to 350 degrees F. Line 12 cupcake tins with paper liners.
Mix the flour, cocoa powder, baking soda and salt together and set aside.
Using an electric mixer, beat the butter with the sugar at medium-high speed until fluffy, 4 minutes. Beat in the egg and vanilla. Working in two batches, alternately fold in the dry ingredients and the wine, until just incorporated. Divide the batter between the cupcake cups and bake for 20 minutes or until a toothpick inserted in the center comes out clean. Let cool completely. The wine flavor mellows a bit upon standing, so I recommend eating these a few hours after you make them.
Prepare frosting. Mix together the butter, cocoa powder, and sugar. Stir in the milk. Beat until light and fluffy. Beat in vanilla. Frost the cupcakes.