Preheat oven to 350°F (175°C). Grease an 8-inch square baking pan.
Place the chocolate and butter in a microwave-safe bowl. Heat at half-power in the microwave in 30-second increments until the butter has melted and the chocolate melts when stirred. Stir until smooth. Set aside to cool slightly.
Mix the sugar and eggs in a large mixing bowl until thoroughly combined. Add the cooled chocolate mixture and the wine, and mix well. Add the flour and salt, and mix just until combined.
Transfer the batter to the prepared pan and spread evenly. Bake 35 to 40 minutes, or until a pick inserted into the center comes out with moist crumbs. Cool in the pan for 10 minutes before cutting into bars.