my man turned 35 this year! this post is a little late (well, honestly, a lot late), since his birthday was way back at the beginning of march, but at least the cake was ready in time for his celebration.
i'm only getting around to posting it now, in part because this really is a special occasion cake. it took me a full afternoon to make this, and nearly as long to type up the recipe and make sure i had it just right, but if you want to make someone feel really special on their day, it's so worth the time and effort. it's an unexpected flavor combo that really works beautifully—the nutty, toasty seeds and sweet-tart bite of the blood oranges—and though really simple to make, the candied orange slices on top give this cake a fancy feel.
for the cake:
Butter (or cooking spray), for the pans
8 eggs, separated
5 ounces (about ¾ cup) granulated sugar
5 ounces (about ¾ cup) dark brown sugar
7 ounces black sesame seeds
6 ounces all-purpose flour (just under 1 ¼ cups)
½ teaspoon salt
for the icing:
4 fluid ounces egg whites (from about 4-5 large eggs)
2/3 cup granulated sugar
2 sticks (1 cup) unsalted butter, softened and cut into chunks
5 tablespoons blood orange curd, plus more for filling the cake between layers
5 tablespoons blood orange simple syrup
for the candied blood oranges & simple syrup:
1 cup granulated sugar
3 cups (24 fluid ounces) water
3 blood oranges, thinly sliced
how to do it:
1. make the candied blood orange slices and simple syrup: put water and sugar in a large sauce pot and bring to a boil over medium-high heat. turn the heat down to medium, add orange slices, and simmer until sugar is totally dissolved, liquid becomes syrupy, and oranges become translucent, about 20-25 minutes. turn off heat and remove orange slices to a baking rack to cool and drain. save leftover syrup and set aside to cool.
2. make the cake: preheat the oven to 350° f. whip egg whites and salt in the bowl of a stand mixer with a whisk attachment on medium speed until they are white and opague (soft peaks stage). Add granulated sugar and whip again until egg whites hold a firm peak. Transfer to a clean bowl and set aside.
3. pulse sesame seeds in a food processor or spice grinder until finely chopped. combine in a medium bowl whisk dark brown sugar and egg yolks. stir in the flour, ground sesame seeds, and salt. then gently fold in the whipped egg whites with a rubber spatula, taking care to deflate them as little as possible; mix until just combined.
4. grease two 10-inch springform cake pans and pour half the batter into each pan. Bake at 350° F for about 15-20 minutes, or until risen, slightly browned around the edges, and firm to the touch. let cool for at least 20 minutes before removing from pans.
5. to make the buttercream: put egg whites into a metal mixing bowl or the bowl of a stand mixer. set up a double boiler by placing a saucepot of water on the stove, bringing it to a simmer over medium heat, and placing the mixing bowl filled with egg whites above it. add the sugar, and whisk the egg white and sugar mixture over the simmering pot until it becomes hot to the touch but is still well below boiling (about 130° f).
6. transfer bowl back to the mixer and whip egg whites on medium-high speed until stiff peaks form. turn mixer speed down to medium and whip in the softened butter, a few pieces at a time. once the butter is fully incorporated, throw in the blood orange curd and syrup, a tablespoon at a time, whipping between additions. chill the icing for about 1 hour before spreading or piping onto the cake.
7. to finish: spread a generous amount of blood orange curd onto the bottom cake layer, then stack the second layer on top. spread frosting around the sides with an offset spatula, then spread gently over the top of the cake. place candied orange slices on top and around the sides of the cake to decorate.