This recipe is used in our Rose Petal Cake, Cherry Blossom Cake, and Violet Cassis Cake.
Preheat oven to 400 degrees. Coat two 8-inch-round-by-2-inch-high cake pans with cooking spray; line with parchment and spray again.
In a medium bowl, whisk together cake flour, almond flour, and salt; set aside.
Heat eggs, yolks, and sugar in a heatproof mixer bowl set over a pot of simmering water; whisk until sugar is dissolved and mixture is warm, about 2 minutes. Attach bowl to mixer; whisk on medium speed for 2 minutes. Raise speed to high, and beat until pale and thick, 4 to 5 minutes. Remove from mixer, and sift flour mixture over eggs; gently fold in using a rubber spatula. When almost incorporated, slowly add melted butter in a steady stream, and continue to fold until completely incorporated.
Divide batter evenly between prepared pans, and bake until cakes are golden brown and springy to the touch. Transfer baking sheets to wire rack and let cakes cool completely.
Run knife around sides of cooled cakes and invert, removing parchment.