Raspberry Chocolate Cake

5 from 2 votes

A tall and decadent Raspberry Chocolate Cake combines two of our favorite flavors for a wonderfully rich celebration cake that is perfect for all occasions! Made with homemade raspberry filling, layers of from-scratch devil's food chocolate cake, and a fantastic chocolate buttercream frosting, this cake is a showstopper that will have everyone raving!

Prep Time45

Cook Time30

Cooling Time1

Total Time2 15

Course: Dessert

Cuisine: American

Servings: servings

Calories: 1026kcal

Author: Amy Nash

Ingredients

Cake

⅓ cup natural unsweetened cocoa powder (35g)
4 ounces bittersweet or semisweet chocolate, finely chopped
1 cup boiling water
1 cup buttermilk (236mL)
½ cup salted butter, softened (114g)
½ cup vegetable oil
1 cup firmly packed brown sugar (200g)
1 cup granulated sugar (200g)
3 large eggs, room temperature
2 teaspoons vanilla extract
2 ¼ cups all-purpose flour (281g)
1 teaspoon baking soda
½ teaspoon salt

Raspberry Cake Filling

12 ounces fresh or frozen raspberries
½ cup granulated sugar (100g)
2 Tablespoons cornstarch
1 Tablespoon lemon juice
1 Tablespoon water

Chocolate Frosting

2 cups salted butter, softened (454g)
7 cups powdered sugar (840g)
1 cup natural unsweetened cocoa powder (100g)
½ teaspoon salt
1 Tablespoon vanilla extract
½ cup heavy cream or whole milk

Instructions

Cake

Preheat the oven to 350°F. Prepare three 8-inch round cake pans by cutting circles of parchment paper to line the bottoms, then lightly spray the insides of the pans with cooking spray.
Combine the cocoa powder and finely chopped chocolate in a large bowl. Pour the boiling water over the chocolate and stir until the chocolate is completely melted. Once cooled, add the buttermilk to the chocolate mixture.
In the large bowl of a stand mixer, beat the butter and oil together for 1 minute. Add the dark brown and granulated sugars and beat for another 2-3 minutes, until light and creamy. Scrape down the sides of the bowl and add in the eggs, one at a time, beating well after each addition and scraping down the sides of the bowl. Add the vanilla extract.
In a separate bowl, sift together the flour, baking soda and salt. Add half of this to the batter and mix on low speed just until combined. Pour in half of the chocolate-buttermilk mixture and mix again, just until combined, then repeat with the flour and the remaining chocolate-buttermilk mixture, scraping down the sides of the bowl between additions, until everything is incorporated.
Divide the batter between the two prepared cake pans and bake for 30 to 35 minutes, or until a toothpick or cake tester comes out clean. Be sure not to overbake.
Transfer the cakes to wire racks and allow them to cool completely before assembling the cake with frosting.

Filling

Combine raspberries and sugar in a medium saucepan over medium heat. Cook, stirring frequently, until the raspberries release their juices and break down, about 8-10 minutes.
In a small, separate bowl, whisk together the cornstarch, lemon juice, and water to create a slurry. Add to the raspberry mixture while stirring and continue to cook another 1-2 minutes until thickened and goes from cloudy to clear. The filling will continue to thicken as it cools, so it shouldn't be too thick and paste-like in the pan. Remove from heat and cool completely before using to fill a cake.

Frosting

In a large bowl, cream the butter for 2 minutes using an electric mixer. Add the powdered sugar and cocoa powder and mix again at the lowest speed until combined.
Add the salt, vanilla, and milk or cream and increase the speed to medium, mixing until the chocolate buttercream is light and fluffy, about 3 minutes. For a softer frosting, increase the milk or cream by small increments., half a tablespoon at a time. Makes enough to frost a three-layer cake with some leftover for piping swirls on top.

Assembly

If any of the cakes are domed on top, use a cake leveler or long serrated knife to level off the tops of each layer.
Place the bottom layer on the cake plate you plan to use. Transfer some of the chocolate frosting to a piping bag fitted with a large open piping tip. Pipe a border around the top of the first layer of cake to create a barrier that will hold in the raspberry filling.
Spoon a layer of the cooled raspberry filling on top of the cake and spread in an even layer contained by the buttercream border.
Finish with a final layer of cake and freeze for 20 minutes. This helps set the buttercream border to contain the filling better to you don't risk as much squishing out when frosting the cake.
Use some of the frosting to do a thin coating of frosting around the top and sides of the cake. Stick the cake back in the freezer for 20 minutes to help set the frosting before adding a final layer of frosting.
Once the crumb coat is set, add more frosting on the top and sides of the cake, spreading it in a smooth, even layer with a large offset spatula or using a knife to create swirls for a more rustic look. Add any remaining frosting to a piping bag fitted with a decorative tip to pipe swirls around the top of the cake and decorate with reserved fresh raspberries.

Notes

Freezing: This cake freezes well and will keep for 2-3 months if properly stored in the freezer. To freeze the whole cake, stick it in the freezer for 30-45 minutes until the frosting is completely set, then wrap the cake with plastic wrap directly on the frosting. It won't stick if the frosting is already frozen. To thaw, pull the cake out of the freezer and remove the plastic wrap. It usually takes about 6 hours to thaw a whole cake. Individual slices can be frozen in a similar fashion and won't take as long to thaw.
Substitutions: You can replace the raspberries with blackberries, strawberries, or blueberries.
Buttermilk substitute: If you don't have buttermilk, just add 1 teaspoon lemon juice or vinegar to a 1 cup measuring cup, then fill it the rest of the way with milk. Let sit for 5 minutes before using.

Nutrition