This was a very fun challenge. I have Dorie Greenspans "Paris Sweets" book and love it. I was going to try this recipe soon, and I am glad I waited. It's apparent that I didn't read the part of keeping the recipe light in flavor. I couldn't find my print out of instructions sooooo I went to the source, the book. I had only one problem with the buttercream, I let it boil a wee bit to long and it started to smoke a little, I thought it would be fine and add a taste of carmel to the buttercream filling................well it tasted like burnt coffee, not pleasant at all!! I made another batch and everything was fine and way better tasting! I blanched the almonds and then had to dry them in the oven for about an hour or so on 300. I let them cool and then ground them for the sponge. This was very time consuming recipe, but totally worth it. The end result was wonderful. I had fun with every step of the process and made mental notes as to what I will change with the next Opera cake. My taste testers LOVED the cake. Everyone had the same response to the first bit, "it was just ok" then the second bit hooked them. The complexity of the textures and flavors was fantistic! The entire cake was gone in 2 days. My tennis buddies were waiting for their taste test pieces and I had to make something else for them later in the week. The family and friends are now waiting for the next month's challenge. I am starting to worry the list of tasters is starting to get long. :o} You can find the recipe on the Daring Bakers Kitchen website, or in Dorie Greenspans book "Paris Sweets".