Instructions

1 In the top of a double boiler, melt unsweetened chocolate and 3/4 cup butter, stirring occasionally, until smooth. Set aside to cool to room temperature. Preheat oven to 350 degrees F (175 degrees C). Grease a 10 inch Bundt or tube pan.

2 In a large bowl, beat egg yolks and 3/4 cup sugar together with an electric mixer on High speed until light and fluffy, about 5 minutes. Gradually stir in the 3/4 cup of port wine and flour. Fold in the cooled chocolate mixture.

3 In a clean bowl, whip egg whites with cream of tartar until frothy. Gradually whisk in 3 tablespoons sugar, and continue to whip until stiff peaks form. Fold 1/3 of the whites into the batter, then quickly fold in remaining whites until no streaks remain. Quickly fold in walnuts. Pour batter into prepared pan.

4 Bake in the preheated oven for about 45 minutes, or until tested done with a toothpick. Cool in pan 10 minutes. Invert onto serving plate. Cool completely.

5 To make the glaze: In the top of a double boiler, over lightly simmering water, combine chocolate chips, 1/2 cup butter and corn syrup. Stir frequently until chocolate is melted. Stir in the remaining 1/2 cup port wine and vanilla until mixture is smooth. Set aside to cool for about 30 minutes. Pour glaze over the cooled cake.