1½ sticks unsalted softened butter
3 cups sugar
2 teaspoons pure Vanilla
4 ozs unsweetened chocolate, melted
3 cups flour
3½ teaspoons baking soda
½ teaspoon salt
¾ cup buttermilk
1⅓ cups boiling water
16 ozs semi-sweet chocolate chips or other semi-sweet chocolate
1½ cups heavy cream
2 tablespoons butter, in pieces
1 teaspoon pure vanilla
Preheat oven to 350º
Butter three 9" cake pans, dust with fine-grained sugar or flour
Bake 35 minutes, until cake-tester comes out clean
Beat together butter and sugar on medium speed until light and fluffy; add eggs and vanilla; beat until well blended.
Add chocolate and beat 1 to 2 minutes on medium speed.
Whisk together flour, baking soda, and salt.
Add flour mixture and buttermilk alternately to egg/sugar mixture alternately, beginning and ending with dry ingredients.
With the mixer on low speed, add boiling water and beat until smooth (batter will be thin).
Pour equal amounts into the three prepared pans, spreading to be flat in the pans.
Cool pans 10 to 15 minutes, then remove from the pans and cool on cooling rack.
Combine chocolate and chips in a 2 quart Pyrex measuring cup; heat in the microwave on High 3 minutes, or until melted; stir in butter and vanilla.
Cover and refrigerate 1 to 1½ hours, or until ganache holds its shape and is thick enough to spread.