Heat oven to 350°F. Lightly grease 10 inch fluted bundt pan with Pam w/flour and sprinkle with unsweetened cocoa.
In a pot combine water, butter, oil and bittersweet chocolate. Cook over low heat 8 to 10 minutes, stirring constantly, until chocolate is melted and mixture is smooth.
Remove from heat. Transfer to a mixer and stir in sugar until blended. Cool 10 minutes.
In a bowl, combine flour, cocoa powder, hot chocolate mix, baking soda and salt.
Add eggs to the cooled chocolate, one at a time. Beat well with whisk.
Add flour mixture alternately with buttermilk, stirring just until blended.
Add vanilla.
Pour batter into pan.
Bake *45 to 50 minutes or until toothpick inserted in center comes out clean.
Cool 15 minutes; remove from pan to cooling rack. Cool completely, about 2 hours.