Vegan Chocolate Cake and Frosting

For kids and adults with food allergies, finding a vegan birthday cake that’s not dry and tasteless can be exhausting. The search is over thanks to this vegan chocolate cake with vegan chocolate frosting. It’s so rich and delicious; no one will suspect it’s dairy-free. Make the frosting just before you’re ready to frost the cooled cake; it’s soft to work with at first, but the frosting will harden slightly as it sits at room temperature.

For the cake:
2 cups all-purpose flour, plus more for coating the pans
2/3 cup natural unsweetened cocoa powder
2 teaspoons baking powder
1 teaspoon baking soda
½ teaspoon fine salt
2 ounces natural unsweetened chocolate, finely chopped (about ¼ cup)
2 cups plain, unsweetened soy or rice milk
2 teaspoons cider vinegar
2 sticks (8 ounces) unsalted, nonhydrogenated margarine, at room temperature, plus more for coating the pans
1 cup packed dark brown sugar
2/3 cup granulated sugar
1 tablespoon vanilla extract

For the frosting:
1 pound vegan bittersweet chocolate, finely chopped (about 3¼ cups)
4 sticks (1 pound) unsalted nonhydrogenated margarine, at room temperature
2 2/3 cups powdered sugar, sifted
¼ teaspoon fine salt
½ cup natural unsweetened cocoa powder
6 tablespoons soy or rice milk
1 tablespoon vanilla extract

1. For the cake: Heat the oven to 350°F and arrange a rack in the middle. Coat 2 (9-inch) round cake pans generously with margarine. Line the bottom of each pan with a round of parchment or waxed paper, then coat the paper with more margarine. Dust the pans all over with flour, tapping any excess out; set aside.
2. Sift the measured flour, cocoa powder, baking powder, baking soda, and salt into a medium bowl; set aside.
3. Using a microwave or double boiler, melt the chocolate in a small bowl; set aside to cool slightly. In a medium, nonreactive bowl, combine the soy or rice milk and vinegar; set aside.
4. In the bowl of a stand mixer fitted with a paddle attachment, beat the margarine and sugars on medium-high speed until fluffy and well combined, about 3 minutes, stopping as needed to scrape down the sides of the bowl. With the mixer on medium speed, add the melted chocolate and vanilla and beat until just combined. Scrape down the sides of the bowl. Reduce the speed to low, add a third of the flour mixture, and mix until just incorporated. Add a third of the soy milk mixture and mix until just incorporated. Continue with the remaining flour and soy milk mixtures, alternating between each and stopping to scrape down the sides of the bowl as needed, until all ingredients are just incorporated.
5. Divide the batter between the prepared pans and spread the tops evenly with a spoon or spatula. Bake until a toothpick inserted into the center comes out clean, about 30 to 35 minutes.
Remove from the oven and let the cakes cool in their pans on a rack for 10 minutes. Slide a thin paring knife around the edges, invert the cakes onto the rack, remove the bottom round of paper, and cool completely.
6. For the frosting: Using a microwave or double boiler, melt the chocolate in a medium bowl; set aside to cool.
7. In the bowl of a stand mixer fitted with a paddle attachment, beat the margarine on medium-high speed until fluffy, about 2 minutes, stopping to scrape down the sides of the bowl. Turn the mixer to low, add the sugar and salt, and mix until incorporated. Increase the speed to medium high and beat until fluffy, about 3 minutes, stopping to scrape down the sides of the bowl.
With the mixer on low, gradually add the cooled melted chocolate and beat until incorporated. Stop the mixer and add the cocoa powder, soy or rice milk, and vanilla. Beat on low until incorporated, then beat on medium high until the frosting is airy and thoroughly mixed, about 1 minute, stopping once to scrape down the sides of the bowl.
8. To assemble: Transfer one of the cake layers, bottom side up, to a serving plate, 9-inch cardboard round, or cake stand. Spoon a third of the frosting into the center of the cake layer. Work an offset spatula or wide butter knife in a gentle swirling motion and spread the icing into an even layer from the center toward the edges of the cake (if you need to add more icing, add it to the center and work it out toward the sides).
9. Carefully set the second cake layer on top of the first, bottom side up. Evenly spread another third of the frosting over the top and sides of the whole cake. (Don’t worry about looks at this point—this is just a thin basecoat, a.k.a. a crumb layer, and it will be covered up later.) Place the cake in the refrigerator until the frosting on the outside is slightly hard, about 15 minutes.
Remove from the refrigerator and evenly spread the remaining frosting over the top and sides of the cake. 1 double-layer 9-inch cake (10 to 12 servings). –Jill Santopietro for CHOW.com.