Chocolate Cake with White Chocolate Frosting
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This fudgy chocolate cake is incredibly moist with a rich chocolate flavor. It’s topped with creamy white chocolate frosting for the ultimate chocolate cake. Incredibly decadent and perfect for chocolate lovers!
Rich dark chocolate and creamy white chocolate come together in this decadent chocolate sheet cake. This cake takes your classic chocolate cake to the next level with creamy white chocolate frosting and chocolate curls on top. You’ll love how moist and fudgy the chocolate cake turns out, and the frosting is perfect for white chocolate lovers.
For the Chocolate Cake
The recipe starts with classic rich and fudgy chocolate cake. It’s the type of cake that sticks to the back of your fork and has a slightly springy texture. The chocolate flavor comes from cocoa powder. For this recipe, you want to use high quality, Dutch processed cocoa for a richer flavor.
The moisture comes from oil, eggs and buttermilk. The oil keeps the cake moist for longer and ensures that the cake doesn’t become too dense and hard if it’s placed in the fridge. This is because the oil stays as a liquid, instead of hardening in the fridge like butter. Don’t worry – you won’t taste the oil because of the rich chocolate flavor. Buttermilk gives baked goods the softest crumb and reacts with the baking soda for the cake to rise.
Then freshly brewed, strong coffee is added to the batter. The hot coffee activates the cocoa powder to give the cake a more robust chocolate flavor. You won’t taste the coffee in the finished product, but if you’d prefer to skip the caffeine, it can be substituted with boiling water.
For the White Chocolate Frosting
The white chocolate frosting is incredibly creamy with a delicious white chocolate flavor. The flavor of the frosting will be dependant on the quality of the white chocolate that you use. I used Callebaut White Chocolate Callets.
You’ll melt the white chocolate slowly – this is imperative so that it doesn’t bake, burn or become grainy. You can do this either in the microwave or a double boiler. If using the microwave, use 45 second intervals on on medium power. Do not use high power which is the default on most machines. If using a double boiler, ensure that the bottom of the bowl containing the chocolate doesn’t touch the simmering water underneath.
Once the chocolate has cooled, you’ll make the frosting. Beat the butter, powdered sugar and salt – then mix in the cooled melted chocolate. Then you’ll beat in a little whipping cream, and potentially a little more powdered sugar, until the desired sweetness is reached.
I added chocolate shavings and a chocolate curls on top for decoration – but that’s optional. If you’re interested in making chocolate curls – I follow this tutorial.
Recipe Tip
Do not use white chips labeled as “white cream” or “white creme” as these are not flavorful enough for frosting. Make sure that you do not use candy melts, as these are not white chocolate either, and will not provide the necessary flavor. Use high quality, white chocolate, you do not want to select anything that feels waxy.
Make Ahead Tips
I almost always make the cake the day before I plan to serve to save time. Let it cool fully, then cover the pan tightly and store at room temperature or in the fridge overnight.
Make the frosting the day you plan to serve. The cake can be stored at room temperature for 8 hours (as long as your kitchen isn’t too hot or it isn’t in direct sunlight).
If the frosted cake has been stored in the fridge, I recommend letting it sit on the counter at room temperature for about 60 minutes before enjoying. The frosting will harden in the fridge, so it’s definitely better when it’s had some time to soften to room temperature.
- Chocolate Layer Cake
- Mini Chocolate Cake – serves just 4-6 people
- Chocolate Cupcakes
- Flourless Chocolate Cake
Chocolate Cake with White Chocolate Frosting
Equipment
- 9×13 inch (23 x 33 cm) baking pan*
Ingredients
Chocolate Cake
- 2 cups all-purpose flour (250 grams)
- 1/3 cup cocoa powder (23 grams), Dutch process
- 2 teaspoons baking soda
- 1 teaspoon baking powder
- 2 cups granulated sugar (400 grams)
- 1/2 cup vegetable oil (120 ml)
- 2 large eggs
- 2/3 cup buttermilk (160 ml)
- 1/3 cup sour cream (80 ml)
- 1 cup freshly brewed coffee (240 ml)
White Chocolate Frosting
- 6 ounces white chocolate (160 grams)
- 1 cup unsalted butter (225 grams), slightly softened
- 2-3 cups powdered sugar (220-330 grams)
- 1/2 teaspoon salt
- 2-3 tablespoons whipping cream (30-45 ml)
Instructions
Chocolate Cake
- Preheat the oven to 350F (180C). Lightly grease a 9×13 inch (23×33 cm) pan and dust with cocoa powder.
- In a large bowl, sift together the flour, cocoa, baking soda, baking powder and salt. Add in the sugar and whisk together until evenly combined.
- In a separate bowl, whisk together the oil, eggs, vanilla, milk and sour cream until you no longer see lumps of egg. Whisk the hot coffee into the bowl.
- Add the wet ingredients into the dry ingredients and beat together on a low speed for about 1 minute or whisk by hand until smooth. The batter will be thin.
- Pour into the prepared pan. Bake in the middle of the preheated oven for about 30-40 minutes, or until the the top looks set and an inserted toothpick comes out clean or with a few damp crumbs but not gooey cake batter. If you're unsure if the cake is done baking, I recommend continue baking for a few extra minutes because the cake is unlikely to dry out.
- Remove from the oven and cool fully in the pan.
White Chocolate Frosting
- If using chocolate bars or chocolate baking squares, first finely chop the chocolate. Place in a heatproof bowl.
- If using the microwave, microwave for 1 minute on medium power – I used 50% power (do not high power, which is often the default). Remove from the microwave and stir. Continue microwaving for 30 second intervals, stirring between each until smooth. If using a double boiler, place heatproof bowl over a saucepan with about 1/2 to 1 inch of gentling simmering water over low heat. Ensure that the water doesn't touch the bottom of the bowl. Gently stir the chocolate as it melts.
- Allow the chocolate to cool for at least 15 minutes.
- In a large bowl, beat the butter until smooth. Add in 2 cups sifted powdered sugar and the salt. Beat together, starting with the mixer on a low speed and gradually increasing to medium speed. Mix in the cooled white chocolate. Ensure that it isn't warm, otherwise it will melt the butter. Occasionally, turn off the mixer and scape down the sides and bottom of the bowl. Beat in the whipping cream 1 tablespoon at a time, until the desired thickness and flavor is reached.
- Frost the cooled cake with the back of a spoon or an offset spatula.
Notes
- Buttermilk: If you don’t have buttermilk, add 2 teaspoons of distilled vinegar or freshly squeezed lemon juice to 2/3 cup milk. Whisk together and let it sit for 5 minutes before using.
- Coffee: Can be substituted with almost boiling water.
- White Chocolate: Use high quality white chocolate. Do not use chocolate chips labeled “white cream”, any white chocolate that feels waxy, or candy melts.
- Storage: Store leftovers in an airtight container at room temperature for up to 2 days or in the fridge for up to 4 days. If the frosting is in the fridge, it will harden. I recommend taking the cake out of the fridge about 1 hour before enjoying so that the frosting can soften.
- Nutrition: Details provided are an estimate only based on 1 slice, assuming the cake is sliced into 15 uniform slices. This cake is very rich, so likely you can get 18 slices or more.
