Melt chocolate in a microwave-safe bowl at HIGH for 30-second intervals until melted (about 1 1/2 minutes total). Stir in chocolate syrup until smooth.
Beat butter at medium speed with an electric mixer until creamy. Gradually add sugar, beating at medium speed until light and fluffy. Add eggs, 1 at a time, beating just until blended after each addition.
Sift together flour, baking soda, and salt. Add to butter mixture alternately with buttermilk, beginning and ending with flour mixture. Beat at low speed just until blended after each addition. Stir in vanilla and melted chocolate just until blended. Pour batter into a greased and floured 14-cup Bundt pan.
Bake at 325° for 1 hour and 20 minutes or until a long wooden pick inserted in center comes out clean. Cool cake in pan on a wire rack 15 minutes; remove from pan to wire rack, and let cool 30 minutes or until completely cool. Garnish, if desired.
I have to agree with an earlier review that the chocolate taste was not very good. The texture and moistness was perfect, but the taste did not live up to the cake itself. I used the Semi-sweet Baker's chocolate and Hershey's syrup. I also had to use a 12 cup bundt cake and adjust the time as well. The icing, well, it did not work out either. It was way too thick at first and then too runny. No happy medium and I should have used clear vanilla as it had a tint to it. I'm tossing this one out of my holiday recipes. Sorry....