This lavender cake with creamy lemon curd and vanilla buttercream comes from Amy Ho’s new book, “Blooms and Baking.”
Make the lavender cake. Preheat the oven to 350 degrees. Grease three 6” round cake pans, line them with parchment paper, and set them aside.
In a medium bowl whisk together the flour, cornstarch, baking powder, baking soda, lavender, and salt. Set the flour mixture aside.
In a medium measuring cup, combine the milk, sour cream, and vanilla. Set the milk mixture aside.
In a stand mixer fitted with a paddle attachment, beat the butter on medium speed until it is creamy, about 1 minute. Add the granulated sugar and beat the ingredients for about 1 minutes, until the mixture if fluffy and pale in color. While the mixer is running, add the eggs and egg yolks, one at a time, making sure each egg is incorporated before adding the next. Stop the mixer and add half of the flour mixture and half of the milk mixture. Mix on low until the ingredients are just incorporated. Add the remainder of the flour mixture and the milk mixture and mix until they are just combined with the egg mixture, about 45 seconds.
Pour the batter into the prepared cake pans. Bake the cakes for 34 to 36 minutes, or until a toothpick inserted into the centers comes out clean. Cool the cakes on a wire rack for about 15 minutes before removing the cakes from their pans to cool completely.
Make the vanilla buttercream. In the bowl of a stand mixer fitted with a paddle attachment, beat the butter on medium-high speed until it is creamy, about 1 minute. With the mixer on low, add the powdered sugar, 1 cup at a time. Add the milk and vanilla. Beat the buttercream at high speed until it is fluffy, about 3 minutes. Transfer 1 cup of the buttercream to a pastry ag fitted with a large round piping tip.
To assemble the cake, trim off the tops of the cake layers with a serrated knife if the tops are rounded. Place the first layer of the cake on a cake stand or plate. Pipe a ring of vanilla buttercream around the top of the cake layer. Fill the center with some of the chilled lemon curd. Place the second layer of cake on top of the first and repeat this process, topping the second layer of filling with the third cake layer. Frost the top and sides of the cake with the remainder of the buttercream. Decorate with flowers of choice.