Lemon Chiffon Cake With Lemon Buttercream Icing and Lemon Curd Filling ( or as I like to call it Tres Lemon Cake)
Preheat oven to 350 degrees. Butter and Flour your pans. I used two ten inch round pans, you can use square, or 8 inch pans.
In a large bowl combine flour, baking powder, salt and 1/2 c sugar. Add oil, egg yolks, sierra mist, lemon juice and zest. Beat with a whisk until smooth (or use mixer).
In a small bowl, beat egg whites and cream of tartar until peaks form. Gradually add 3/4 cup sugar, and beat until stiff and shiny peaks form. Fold 1/3 of the whites into the batter, then quickly fold in remaining whites until no streaks remain. Turn into greased pan and bake at 350 degrees for about 45 minutes. Time of cooking depends on the size and shape of pan. My cakes cooked in about 45 minutes for 10 inch rounds.
For the Icing:
Beat the butter until smooth. Add powdered sugar (make sure the mixer is off) and slowly blend until creamy and well combined about 2 minutes. Add zest, juice, vanilla and whip for an additional minute. Add 4 Tbs. heavy whipping cream and whip for about 2-3 minutes until light and fluffy. To darken the icing to a yellow add a few drops of icing coloring (available at Joanns or Michael's).
To put the cake together:
Cool the cake layers completely. Cut them in two with a serrated knife. Layer on round on a cake platter. Spread 1/2 a jar of lemon curd and add the next layer (there will be four layers total). Add some icing. Layer another piece using the remaining 1/2 jar of lemon curd. Cover with final layer and frost the cake any way you like! I added a slight bit of yellow coloring to the remaining icing and used it to pipe around the cake and add wording. Then I sliced a lemon very thinly and twisted them, placing them around the top of the cake. Enjoy!