Anniecahill, I am posting the Vanilla Buttermilk recipe I have. It's about the same ingredients as the Dede one you posted, but mixed differently. It has vanilla extract as the flavoring which you could try as is, or you could substitute for lemon oil. Maybe you want to try this one and see if it's comparable to the other one.
This one has less egg whites than yolks for moistness.
Vanilla Buttermilk Cake
Sky High: Irresistible Triple-Layer Cakes
This might be one of the best yellow cakes to come out of my kitchen, and I will certainly be coming back to it to try it in cupcake format soon. My notes are the same as for the chocolate cake above: you cannot scrape the bowl down enough. Otherwise, the cake is really quite simple, a relief when youve got, oh, 6 layers of it to bake.
Makes one three-layer 9-inch round cake [Equivalent in batter to an 8-inch square; we scaled it up for a 10-inch square/middle tier of the wedding cake]
3 3/4 cups cake flour
2 1/2 cups sugar
1 tablespoon plus 2 3/4 teaspoons baking powder
1/2 teaspoon salt
2 1/2 sticks (10 ounces) unsalted butter, at room temperature
1 1/4 cups plus 1/3 cup buttermilk
5 whole eggs
2 egg yolks
2 1/2 teaspoons vanilla extract
1. Preheat the oven to 325°F. Butter three 9-inch round cake pans. Line the bottom of each pan with a round of parchment or waxed paper and butter the paper.
2. Combine the cake flour, sugar, baking powder, and salt in a large mixer bowl. With the mixer on low speed, blend for 30 seconds. Add the butter and 1 1/4 cup of the buttermilk. Mix on low speed briefly to blend; then raise the speed to medium and beat until light and fluffy, 2 to 3 minutes.
3. In a smaller bowl, whisk together the whole eggs, egg yolks, vanilla, and the remaining 1/3 cup buttermilk until well blended. Pour one-third of the egg mixture into the cake batter at a time, folding it in completely after each addition. There will be 9 cups of batter; our 3 cups batter into each pan.
4. Bake for 26 to 28 minutes, or until a cake tester or wooden toothpick inserted in the center comes out clean.
5. Turn the layers out onto wire racks by placing a rack on top of a pan, inverting it, and lifting off the pan. Peel off the paper liners and let cool completely. When the layers have cooled, place a cardboard cake board on top of a layer, invert again, and lift off the rack. To make the layers easier to handle, wrap them on their boards completely in plastic, so they dont dry out, and refrigerate them.
I have the Sky High book, but I'm posting this here, because it's already out there on the internet.
This is the link to the blog:
http://smittenkitchen.com/2008/07/project-wedding-cake-the-cake-is-baked/