Welcome to BA Bake Club, a community of curious bakers. Each month senior test kitchen editors Jesse Szewczyk and Shilpa Uskokovic share a must-make recipe and dive deep on why it works. Come bake and learn with us—ask questions, share pics, listen to our podcast, and lots more here.
This one-bowl, no-mixer-needed chocolate cake has a secret up its sleeve: extra-virgin olive oil. Yes, the same oil used in vinaigrettes. An unexpected complement to dark chocolate, it lends the cake—and the ganache-like frosting—a floral complexity and grassy pepperiness. And used in place of butter, olive oil ensures that the cake crumb will stay plush and moist for several days. See if your friends can guess the ingredient on their own. Finishing with a sprinkle of flaky sea salt tames the sweetness, and ranks as one of the easiest decorations ever. It’s simple and worthy of a celebration at the same time. To amp up the chocolate flavor even more, add 1 tsp. instant espresso powder to the ¾ cup water in Step 1, stirring to dissolve completely. And make sure you use a high-quality cocoa powder—our test kitchen’s favorite is Guittard Cocoa Rouge.
Recipe information
Total Time
8 servings
Yield
1 hour 20 minutes
Ingredients
Cake
Frosting and Assembly
Preparation
Cake
Step 1
Place a rack in middle of oven; preheat to 350°. Lightly coat a 9"-diameter cake pan or 8x8" baking pan with nonstick vegetable oil spray; line with a parchment paper round if using a cake pan or a sheet of parchment if using a square pan. Whisk together 1½ cups (300 g) granulated sugar, 1⅓ cups (167 g) all-purpose flour, ½ cup (57 g) Dutch-process cocoa powder, 2 tsp. Diamond Crystal or 1¼ tsp. Morton kosher salt, and ¾ tsp. baking soda in a large bowl. Add 2 large eggs, ½ cup buttermilk, ½ cup extra-virgin olive oil, 1 Tbsp. vanilla extract, and ¾ cup water and whisk until no pockets of unincorporated flour or cocoa powder remain.
Step 2
Scrape batter into prepared pan and bake cake, rotating pan halfway through, until a tester inserted into the center comes out with just a few moist crumbs attached, 38–45 minutes. Transfer pan to a wire rack and let cake cool in pan 15 minutes. Turn out cake onto rack and let cool completely.
Frosting and Assembly
Step 3
Microwave 6 oz. unsweetened chocolate, chopped, ¼ cup extra-virgin olive oil, 1 Tbsp. vanilla extract, ¾ tsp. Diamond Crystal or ½ tsp. Morton kosher salt, and ½ cup water in a large microwave-safe bowl in 20-second bursts, stirring after each burst, until chocolate is melted. Vigorously whisk mixture until mostly smooth; mixture will look oily and broken, but that is okay. (Alternatively, heat in a heatproof bowl set over a saucepan of simmering water, whisking until melted and mostly smooth. Do not let bowl touch water.) Add 2 cups (220 g) powdered sugar and whisk until dissolved and mixture is completely smooth. Chill, stirring with a rubber spatula every 5 minutes to promote even cooling, until frosting is room temperature and looks like soft fudge, about 20 minutes. (Frosting needs to be room temperature to swoosh properly. If it gets too cold, microwave 5 seconds and stir to thin out.)
Step 4
Place cake, upside down, on a cake stand or large plate. Spoon frosting on top and spread with a spoon or offset spatula to create dramatic swooshes; sprinkle with flaky sea salt.
Step 5
To serve, cut into individual slices and drizzle with oil if desired.