Serves 10
THE “SCOTT” OF THIS CAKE IS MY DARLING HUSBAND. WHEN HIS FIRST BIRTHDAY AS a married man rolled around, it was mid-September and it was hot in our little un-air-conditioned apartment in Los Angeles. But scorching temperatures be damned, I was determined to demonstrate my domestic abilities as a newly minted wife and bake him a birthday cake from scratch. Thanks to blind moxie and a complete lack of experience in making layer cakes, I didn’t consider the effect of heat on tender cake rounds and soft buttercream. The stacked cake layers split into fourths soon after the frosting was applied—I tried in vain to pin the cake together with toothpicks and solder the whole droopy creature in the freezer, to no avail. The birthday cake was really more of a birthday pile that year, with candles haphazardly stuck in it. We laughed and I cried a little. But it was still insanely delicious. And that is a testament to how extraordinary this cake really is.
Over the years I’ve tweaked the recipe for texture and taste, and become much better at building layer cakes. Even though it’s so fabulous it deserves to be paraded out for every dinner party, picnic, bake sale, and other random people’s birthdays, I save this chocolate behemoth for just once a year, in honor of my favorite husband.
Nonstick cooking spray for pans
2¼ cups/270 g cake flour, spooned and leveled
1½ teaspoons baking soda
1 teaspoon fine sea salt
1 cup/226 g unsalted butter, at room temperature
1½ cups/300 g granulated sugar
1 teaspoon pure vanilla extract
4 ounces/113 g bittersweet chocolate (70% to 72% cacao), melted and cooled
3 large eggs
⅓ cup/75 g vegetable or canola oil
1 cup/225 g cold water
3 cups/360 g confectioners’ sugar, sifted
1½ cups/339 g unsalted butter, at room temperature
2 tablespoons whole milk or cooled brewed coffee
1½ teaspoons pure vanilla extract
Generous ½ teaspoon fine sea salt
6 ounces/170 g bittersweet chocolate (70% to 72% cacao), melted and cooled
2 ounces/57 g semisweet chocolate, finely chopped, plus more for sprinkling (optional)
Position an oven rack to the center of the oven and preheat it to 350°F/180°C. Coat two 8-inch/20 cm round cake pans with nonstick cooking spray, line the bottoms of the pans with circles of parchment paper, and then spray again for extra nonstick insurance.
Sift together the cake flour, baking soda, and salt into a large bowl.
In the bowl of an electric mixer fitted with the paddle attachment, on medium-high speed beat together the butter, granulated sugar, and vanilla until light and fluffy, about 3 minutes. Add the melted chocolate and beat for 1 minute to blend. In a small bowl, whisk together the eggs and oil until emulsified. On medium speed, beat the egg mixture into the chocolate mixture. Continue to beat to a light, mousselike texture, about 2 minutes.
Gradually mix in the flour mixture in 3 batches, alternating with the cold water and mixing for 30 seconds after each addition. When all of the flour mixture and water has been added, scrape the bowl once more and then mix for 1 minute more on medium speed, or until the batter is smooth and mousselike once again. It should look like clouds of chocolate.
Pour the batter evenly into the prepared pans until about two-thirds full, and smooth the surfaces with a spatula. Bake until the cakes spring back when touched and a cake tester comes out clean, about 35 minutes. Let the cakes cool in the pans on a rack for at least 40 minutes. Turn out the cooled layers onto a parchment-lined baking sheet, wrap with plastic wrap, and chill for 1 hour, or up to 1 day ahead—this is a very tender cake and the chilling time makes it easier to frost.
Meanwhile, prepare the buttercream: In the bowl of an electric mixer with the paddle attachment, combine the confectioners’ sugar, butter, milk or coffee, vanilla, and salt. Beat on medium-high speed until light and airy, at least 3 minutes. Add the cooled bittersweet chocolate. Beat until well blended, 1 minute more. Fold in the chopped semisweet chocolate by hand.
Turn 1 of the cooled cake layers upside-down onto a cake stand and peel away the parchment. Spread about a third of the frosting on this layer. Place the second layer on top and remove the parchment. Apply a thin, almost invisible-in-spots layer of frosting on the outside of the cake as a crumb coat to glue any errant crumbs in place. Chill for 20 minutes to set. Frost top and sides of the cake with the remaining frosting. Sprinkle with additional chocolate chunks, if desired.