Combine the cake mix, sour cream, pudding, butter, eggs and buttermilk in a large mixing bowl. Beat 2 minutes or until batter is smooth. Divide batter into 2 bowls. Add vanilla to one bowl and peppermint extract and red food coloring to the other. Mix well.

Grease and flour bundt pan. Add white batter, then top with of red batter. Swirl batters together with the tip of a sharp knife.

Bake at 350 until just done, check at 35 minutes. Cool. Turn cake out onto a cake plate.

Heat cream until hot but not boiling. Pour over chocolate in a measuring cup. Stir to melt chocolate. Poke cake all over with a long skewer. Pour ganache slowly over cake.