We make the cake first, then prepare, assemble, ice, and decorate it.
Sponge Cake
Ingredients
3 1/2 cups cake flour, sifted
2 1/4 cups granulated sugar
4 teaspoons baking powder
1 teaspoon fine-grain sea salt
3/4 cup unsalted butter, cold and cubed
1 1/2 cups whole milk at room temperature
2 teaspoons orange blossom
zest of one lemon
7 lightly beaten egg whites, at room temperature
Instruction:
Preheat the oven to 350°F. Grease and flour two 8-inch round cake pans.
Whisk together the flour, sugar, baking powder and salt in the bowl of an electric mixer fitted with the paddle attachment. Put mixer on low speed and add the cold butter one cube at a time. After all of the butter has been added, let the mixer run on low speed until the flour mixture resembles fine cornmeal, about 5-7 minutes.
While the mixer still running, add half of the milk and the orange blossom extract. Increase speed to medium; mixture will be thick. Add the remaining milk and egg whites. Beat until just combined on medium speed. Stop the mixer and scrape down the edges of the bowl. Fold batter with a rubber spatula until the mixture is consistent, with no streaks or pockets of flour remaining. Divide batter between prepared pans. Bake for 30-35 minutes, or until a toothpick tester comes out clean. Let cool in the pans for 5 minutes before turning onto a wire rack to cool completely. Level the cakes evenly using a cake leveler or large serrated knife. Cut each cake layer horizontally (torte), divide the cake into four equal thin layers.
Elderflower/lemon icing (Works best in a room with cooler temperatures, preferably under 22°C)
Ingredients:
2 cups unsalted butter, softened
6 1/2 cups powdered sugar, sifted
3 tablespoons lemon juice
3 tablespoons Elderflower syrup
zest of one lemon
2 tablespoons of saffron water ( infuse some saffron into 2 tablespoons of hot water ) or a few drops of lemon yellow food colour.
Instructions:
In the bowl of a standing mixer fitted with the whip attachment, beat the butter until creamy. Add the powdered sugar and mix until crumbly. Add the lemon juice and beat again. Add elderflower syrup one tablespoon at a time while beating on medium speed, until the mixture is fluffy and spreadable. Add the lemon zest and mix again. Scrape down the sides of the bowl and fold together any unincorporated pockets of sugar.
Remove half of the icing to a large bowl and cover with a paper towel to prevent the buttercream from crusting.
To the other half, add drops of lemon yellow food colour (one drop at a time) (*we used saffron water but it can be tricky because some saffron can produce an intense yellow colour, while some are quite weak) to the buttercream remaining in the mixing bowl. Beat until a consistent bright yellow colour is achieved. (our was not as bright and we had to photoshop yellow colour in) Transfer the yellow buttercream into a piping bag and snip the end. Evenly pipe buttercream onto three cake layers and stack them.
Apply a thick covering of white frosting over the top and sides of the cake, smoothing the surface with an offset spatula. Refrigerate until the buttercream is firm, about 2 hours.