Ultimate Dark Chocolate Layer Cake with Silky Frosting
This is the ultimate chocolate cake for true chocolate lovers: moist, dark layers paired with a rich, creamy frosting that shines like silk.
- Prep25 min
- Cook35 min
- Total1h
- DifficultyMedium
- Servings12
If you’re looking for a showstopper chocolate cake that’s both decadent and surprisingly simple to make, this is it. The cake itself is deeply chocolatey and tender, thanks to a combination of cocoa powder and sour cream, while the frosting—made with real melted chocolate and a touch of corn syrup—turns out silky, shiny, and absolutely irresistible.
Perfect for birthdays, celebrations, or any day that calls for a serious chocolate fix, this cake stays moist for days. The frosting comes together in a food processor in minutes, and the whole thing can be assembled and enjoyed the same day.
Ingredients
For the Cake
For the Frosting
Converted amounts are rounded.
Method
- Preheat the oven to 350°F with a rack in the center. Lightly butter the bottom of two 9-inch (23-cm) round cake pans. Line the bottoms with parchment paper, then butter and flour the parchment and the sides of the pans. (Alternatively, use a nonstick cooking spray with flour.)
- In the bowl of a stand mixer fitted with the paddle attachment, combine the flour, sugar, cocoa powder, salt, baking powder, and baking soda. Mix on low speed for 30 seconds. Add the eggs, oil, sour cream, and vanilla; mix on low until combined.
- Increase the speed to medium and beat for 2 minutes. Reduce the speed to low and very slowly pour in the boiling water (to avoid splashing). The batter will be thin. Stop the mixer, scrape down the bowl, and mix again until smooth.
- Divide the batter evenly between the prepared pans. Bake for about 35 minutes, or until a toothpick inserted in the center comes out clean. While the cake bakes, make the frosting.
- Let the cakes cool in the pans on a wire rack for 10 minutes. Turn them out onto the rack, remove the pans, and let cool completely. Place one layer on a serving plate and spread about ¾ cup of frosting on top. Top with the second layer, then spread the remaining frosting over the top and sides, swirling decoratively.
- For the frosting: Place the chocolate in a microwave-safe bowl and microwave in 20-second bursts, stirring between each, until about three-quarters melted. Stir until the residual heat melts the rest. Set aside to cool slightly.
- In a food processor, process the butter, confectioners' sugar, cocoa powder, and salt until smooth, about 30 seconds, scraping down the sides. Add the corn syrup and vanilla; process for 5–10 seconds. Scrape down the bowl, add the lukewarm melted chocolate, and pulse until smooth and creamy, 10–15 seconds. Do not overmix.
- Use the frosting immediately or keep at room temperature for 3–4 hours. If it loses its shine, stir with a hot metal spoon (dip in hot water, then dry) to restore the gloss.
💡 Tips
- For a neater slice, chill the cake for 20 minutes before cutting.
- The frosting can be made a day ahead and kept at room temperature; stir well before using.
- If you don't have a food processor, use a stand mixer with the paddle attachment for the frosting.
Inspired by a recipe from Once Upon a Chef