Preheat oven to 350 degrees F. Grease and flour a 12-cup Bundt pan.
Stir together flour, cocoa powder, baking powder and salt.
Beat butter and sugar together in a large mixing bowl, using high speed of electric mixer, until fluffy, then add eggs one at a time, beating well. Beat in vanilla.
Add flour mixture to butter mixture gradually, alternating with wine.
Pour into the pan and bake for 45 minutes. Let the cake cool for about 10 minutes, then carefully turn from the pan. Let cool completely, then drizzle glaze over the top.
To make the glaze, combine the chopped chocolate, butter and corn syrup in a small bowl. Heat the heavy cream just until it starts to bubble. Combine the cream and the chocolate mixture. Let stand for about 3 minutes, then stir until smooth. Let the glaze cool to the point where it's thick enough to drizzle.