Vegan Devil's Food Cake

Melt unsweetened chocolate in top of a double boiler over simmering water, stirring frequently and scraping down the sides with a rubber spatula to avoid scorching. Set aside to cool slightly, about 5 minutes.

Preheat oven to 350 degrees F (175 degrees C). Line two 9-inch cake pans with waxed paper.

Sift cake flour, baking soda, and salt together in a large bowl.

Whisk sugar, water, vegetable oil, vanilla extract, and balsamic vinegar in a large bowl until well-combined. Stir in half of the sifted flour mixture. Fold in melted chocolate. Stir in remaining sifted flour mixture. Beat with an electric mixer on medium speed until batter is smooth, about 2 minutes. Divide batter between cake pans.

Bake in the preheated oven until toothpicks inserted in the centers come out clean, about 45 minutes. Cool in the pans, 5 minutes. Invert cakes onto wire rack and let cool completely before frosting, about 1 hour.