Thanks Kim for sharing this recipe. I made it today for my Grandfather's birthday. It was very good. I did make it last night and it did not rise. Yep, I cannot substitute the buttermilk for soured milk. It has an interesting crumb. It's has a very tight wet crumb. Very good and great coconut flavor! I took your advise on the coconut extract. For the filling, I used coconut cream instant pudding, whipping cream and coconut milk (leftover from another experiment gone bad) plus shredded coconut. My family loved the "coconut custard". The icing was a bit sweet for me; I am not an icing person. I think a IMBC would be great on this cake or maybe just a whipped topping. I will definetely make this one again. THANK YOU SO MUCH!