Dark Chocolate Coconut Sponge Cake
Recipe and photo by Tami Ganeles Weiser
to 10 servings
Prep Time: 45 minutes Cook Time: 30 minutes
Chocolate sponge cakes without any gluten—much less kosher for Passover—are quite rare. I now know why. This recipe was pretty darn challenging to develop and required a fair amount of tweaking and investigation of baking science on my part. I’m happy to report that by George, I think we’ve got it! Cindi my baking-chef-instructor tester and all the tasters were surprisingly pleased with the classic, fluffy foam-cake (foam cake is a rather technical term used to describe cakes made with whipped egg whites for lift) texture, as well as distinctly cocoa taste. Now, be warned: this cake doesn’t taste like a rice-based, gluten-free or matzo-cake-meal Passover cake one little teeny bit. It tastes like real-deal cake. That means great. Now, as to the chocolate ganache, it ramps up the flavors and offers a creamy textural contrast to the crunchy toasted coconut. The ganache can be doubled easily, and spread out from the top layer well over the edges with a large offset spatula to mask any rough edges if you want a refined look. I opted for a more rustic, German chocolate cake-style, with unfrosted sides, but feel free to decorate as you like it.
Dark Chocolate Coconut Sponge Cake:
¾ cup (6 fluid ounces) coconut milk
⅓ cup (32 grams) cocoa powder, sifted, plus more for dusting
½ cup (52 grams) coconut flour, sifted
1 teaspoon (5 grams) baking powder
½ teaspoon (3 grams) salt
8 eggs, separated
½ cup (103 grams) light brown sugar
½ teaspoon (2 grams) cream of tartar
½ cup (102 grams) granulated sugar
¾ cup coconut cream
3 tablespoons coconut oil
18 ounces dark, extra-dark or semi-sweet couverture chocolate (65 to 72 percent chocolate liquor, nondairy preferred), finely chopped (see Kitchen Tips)
2½ cups sweetened, shredded coconut, toasted
- Make the cakes: Preheat the oven to 350°F. Spray 2 (8-inch) round cake pans with nonstick vegetable oil or coconut oil spray and sprinkle about 1½ tablespoons cocoa powder into each. Hold the pans over the sink, swirl the pans to lightly coat the sprayed surfaces with cocoa powder, and discard any excess. Set aside.
- Heat the coconut milk in a small saucepan set over medium heat for 4 to 5 minutes, until it simmers. (You can also do this in a microwavable bowl and microwave on high power for 45 seconds to 1 minute). Remove from the heat and whisk in the remaining cocoa powder until smooth. Allow to cool until the liquid is no longer warm to the touch.
- Meanwhile, sift together the coconut flour, baking powder, and salt onto a large sheet of parchment paper or a mixing bowl and set aside.
- In the bowl of a stand mixer fitted with the whisk attachment (or if you are using a handheld electric mixer, in a mixing bowl) combine the egg yolks and brown sugar and mix at medium speed for 5 to 6 minutes, until the mixture is fluffy and lighter in color and it ribbons—that is, it will thicken enough to adhere to the beaters if you lift them up, but will immediately fall back into the bowl, in ribbon-like streaks.
- When the cocoa mixture has cooled, add it to the egg mixture and mix for another 1 to 2 minutes, until fully incorporated.
- With the mixer running at medium-low speed, add the coconut flour mixture, 2 to 3 tablespoons at a time, spooning it down the sides of the bowl, not onto the beaters (so you don’t have it all fluff and splurt back into your face), and making sure each addition is fully incorporated before adding the next.
- If you are using a stand mixer, transfer the egg yolk mixture to another bowl. Clean the mixer bowl and whisk attachment, working quickly, until they are perfectly clean and dry. If you are using a handheld mixer, use another (perfectly clean and dry) bowl (see Kitchen Tips) and a clean whisk attachment.
- Pour the egg whites into the clean bowl and beat for 15 to 20 seconds, just until foamy. Add the cream of tartar and beat at medium speed for 1 to 2 minutes, until they almost form soft peaks. Then gradually add the granulated sugar, a tablespoon at a time, while continuing to beat at medium speed, which should take about 1 to 2 minutes in a stand mixer or 3 to 4 minutes with a handheld mixer, until the egg white mixture holds stiff, glossy peaks (see Kitchen Tips).
- Add one-third of the egg white mixture into the egg yolk mixture and gently fold (see Kitchen Tips) until combined; it’s fine if you have a few small streaks of egg white in the batter. Add the remaining egg whites and carefully and gently fold them into the chocolate mixture.
- Gently scoop half of the mixture into each of the prepared baking pans. Bake for 20 to 25 minutes, until a toothpick inserted in the center of the cake comes out clean and the cake springs back when lightly pressed with a fingertip. Do not overbake; the cake will continue to bake, dry out, and set firmly as it cools.
- Make the ganache filling and topping: In a medium saucepan set over very low heat, combine the coconut cream, coconut oil, and chocolate and cook, stirring, for 5 to 6 minutes, until about half to two-thirds of the chocolate is melted. Immediately remove the pot from the heat, continue to stir, and let the mixture come to room temperature. It will thicken.
- Place one of the cake layers on a cake dish, top side down. Pour one-third of the chocolate ganache onto the center and spread gently with an offset spatula or blunt knife, without pushing it, but sliding it over the cake, leaving a ¼-inch border around the edge of the cake uncovered. Sprinkle half of the coconut evenly over the top and gently press the flakes into the ganache. Place the second cake layer on the ganache and coconut, top side up. Spread the remaining chocolate ganache over the top, allowing it to drip over the side with a nudge, so the ganache puddles decoratively down the side. Or if you would like frost the cake German chocolate cake-style, spread out the ganache to about ⅛ inch from the edge and top with the remaining coconut.
- Toasted shredded coconut is available in stores, but it’s easy to do yourself. Preheat the oven to 375°F. Scatter the coconut evenly on a rimmed baking sheet and bake, mixing every 3 minutes and watching carefully to make sure that it does not burn, for a total of about 9 minutes, or until lightly browned. Note that sweetened coconut will toast a little faster than unsweetened, so adjust the timing accordingly.
- When beating egg whites, an impeccably clean bowl is a must; even a bit of grease can decrease their volume and stability.
- Egg whites at the soft peak stage will be glossy and foamy, retain their basic shape but will droop a bit, and won’t entirely cling to the bowl. Egg whites at the stiff peak stage will be glossy and very firm, will retain their shape and cling to the bowl. They will stand straight up from the overturned beater. Yet they will still be creamy and flexible enough to fold in with other ingredients.
- Folding is a technique used for combining two mixtures of differing densities. The lighter mixture, usually egg whites or cream, is poured or scooped on top of the heavier mixture, and instead of mixing them around the bowl, the cook gently scoops some of the lighter mixture up from the bottom, catching some of the heavier mixture with it, and very gently turns the whole thing over. Folding rather than beating whipped egg whites or cream into a batter protects the foam and froth created during beating and in doing so, makes the final mixture lighter and fluffier. Here’s a post and video from thekitchn.com that shows just how to do it.