Judith olney's chocolate buttermilk cake

1. I. The cake: Preheat oven to 350 °F. Greasei 3 round, 9" cake pans.
2. Line bottoms with greased wax paper.
3. Sifti together flour, ¾ c cocoa, baking soda, baking powder and cinnamon.
4. Mixi in buttermilk and coffee (dissolve coffee in an equal amount of hot water first).
5. Creami 1 ½ c butter with the sugar until light and fluffy.
6. Add the eggs one at a time until thick.
7. Beatingi on low speed, slowly mix in buttermilk mixture.
8. Beat "til well blended.
9. Bakei about 35 minutes, or until a straw comes out clean.
10. Remove to racks to cool.
11. After they are cooled, put in "fridge".
12. After 1 hour in "fridge", split each in half (see note at bottom).
13. Wrap each layer in wax paper or plastic wrap, and freeze immediately.
14. Ii. Sour creami filling: Beat ¾ c heavy cream, gradually adding ¾ c 10x sugar until stiff.
15. Gently fold in ¾ c sour cream.
16. Set aside in "fridge" (covered).
17. Iii. Chocolatei sour cream frosting: Melt remaining (½ c) butter.
18. Add ½ c 10x sugar and remaining (½ c) cocoa.
19. Stiri with a wire whisk over low heat until smooth; cool.
20. Beat remaining (1 ½ c) heavy cream; add remaining (1 ½ c) 10x sugar until soft peaks form.
21. Add cooled chocolate mixture; beat until stiff.
22. Foldi in remaining (¾ c) sour cream.
23. Iv. Construction: Build layers from the bottom up as follows: Cake, 1/3 the filling, cake, 2/3 c frosting.
24. Repeat above twice, for total of six layers.
25. Put remaining frosting on sides.
26. Chill two hours before serving.
27. Note: the cakes must be well-chilled before assembly, or they will disintegrate under their own weight during assembly.
28. If the cake tops rose during baking, the layers will not stack well.
29. You will need to slice the excess off *after* chilling, but *before* splitting into layers.