Halloween Ghost Cake (Dark Chocolate Blackberry Layer Cake)

A three-layer chocolate cake with pink frosting, topped with blackberries, blueberries, and ghost-shaped meringues, with a slice removed.

Halloween Ghost Cake (Dark Chocolate Blackberry Layer Cake)

This Halloween cake has three dark chocolate layers made with black cocoa, a naturally purple blackberry buttercream (no food coloring), and a topping of fresh berries and homemade meringue ghosts. Every part can be made ahead, so the day of the party is just decorating.

Course Dessert

Cuisine American

Keyword Halloween cake, Halloween chocolate cake, Halloween layer cake

Prep Time 1 30

Cook Time 2 15

Total Time 3 45

Servings slices

Calories 820kcal

Author Julia

Ingredients

For the meringue ghosts

3 large egg whites at room temperature
¼ teaspoon cream of tartar
¾ cup sugar superfine
1 ounce semisweet chocolate or dark chocolate melted

For the dark chocolate cake

3 cups all-purpose flour
3 cups granulated sugar
⅔ cup unsweetened cocoa powder
⅓ cup black cocoa powder
1 tablespoon baking soda
1½ teaspoons baking powder
1 teaspoon salt
4 large eggs at room temperature
1 cup full-fat sour cream at room temperature
½ cup vegetable oil
2 teaspoons vanilla extract
1 cup hot coffee freshly brewed

For the blackberry reduction

3 cups frozen blackberries
2 tablespoons granulated sugar

For the blackberry buttercream

2 cups unsalted butter softened
6 cups powdered sugar
2 teaspoons vanilla extract
½ teaspoon salt
⅓ cup blackberry reduction plus more as needed
1 to 2 tablespoons heavy cream if needed

For decorating

fresh blackberries
fresh blueberries
meringue ghosts

US Customary - Metric

Instructions

Make the meringue ghosts

Preheat the oven to 200°F (95°C). Line two baking sheets with parchment paper.
Place the egg whites in a clean, grease-free mixing bowl. Using the whisk attachment, beat on medium speed until the whites are foamy.
Add the cream of tartar and continue whisking until soft peaks form. When the whisk is lifted, the meringue should form a peak that gently folds over at the tip.
Increase the mixer to medium-high speed. Add the superfine sugar gradually, about one tablespoon at a time, allowing it to mix in thoroughly before adding the next spoonful.
Continue whisking until the meringue is thick, glossy, and holds stiff peaks. Rub a small amount between two fingers. It should feel smooth rather than grainy.
Transfer the meringue to a piping bag fitted with a large plain round tip. Pipe a wide base onto the prepared baking sheet, lift the bag slightly, and pipe a smaller section above it. Ease the pressure and lift the bag upward to create a pointed top.
Bake for 75 to 90 minutes, until the ghosts feel dry and lift cleanly from the parchment. Turn off the oven, prop the door slightly open, and leave the meringues inside for at least 30 minutes. Transfer them to a wire rack and let them cool completely.
Once the ghosts are completely cool, melt the chocolate in a small microwave-safe bowl in short intervals, stirring after each one. Use a clean toothpick, a fine food-safe paintbrush, or the tip of a small piping bag to add eyes and mouths. Let the chocolate set completely before handling or storing the ghosts.

Make the cake layers

Increase the oven temperature to 350°F (175°C). Grease three 8-inch round cake pans and line the bottoms with parchment paper.
In a large mixing bowl, whisk together the flour, granulated sugar, dark cocoa powder, black cocoa powder, baking soda, baking powder, and salt. Break up any lumps of cocoa powder before adding the wet ingredients.
Add the eggs, sour cream, vegetable oil, and vanilla extract. Mix on low speed until mostly combined, stopping to scrape the bottom and sides of the bowl.
With the mixer running on low speed, slowly pour in the hot coffee. Continue mixing just until the batter is smooth and evenly combined. The batter will be thin.
Divide the batter evenly among the prepared cake pans. Gently tap the pans on the counter to release any large air bubbles.
Bake for 30 to 35 minutes, or until the centers spring back when lightly touched and a toothpick inserted into the center comes out clean or with a few moist crumbs.
Let the cakes cool in their pans for 10 to 15 minutes. Carefully turn them out onto wire racks, remove the parchment paper, and let them cool completely. For easier assembly, wrap and refrigerate the cooled layers until chilled.

Make the blackberry reduction

Place the frozen blackberries and granulated sugar in a medium saucepan. Cook over medium-low heat, stirring occasionally, until the berries have thawed, softened, and released their juices.
Blend the mixture until smooth.
Press the purée through a fine-mesh sieve to remove the seeds. Scrape the underside of the sieve to collect all of the smooth purée.
Return the strained purée to the saucepan. Simmer gently, stirring frequently, until it has reduced to about ½ cup and has a thick, jam-like consistency.
Transfer the reduction to a bowl and let it cool completely. Do not add warm reduction to the buttercream.

Make the blackberry buttercream

Place the softened butter in the bowl of a stand mixer fitted with the paddle attachment. Beat on medium-high speed for 4 to 5 minutes, until pale, creamy, and increased in volume.
Add the powdered sugar gradually, mixing on low speed after each addition. Stop and scrape the bowl as needed.
Add the vanilla and salt. Beat on medium speed until the buttercream is smooth and fluffy.
Add the measured blackberry reduction one spoonful at a time, mixing well after each addition. Check the color and consistency. Add a little more reduction for a deeper purple color, but stop if the buttercream begins to soften too much.
If the buttercream is too firm for spreading, add the heavy cream a teaspoon at a time. The blackberry reduction may provide enough moisture that no cream is needed.
Finish by mixing the buttercream on the lowest speed for 2 to 3 minutes. This removes large air bubbles and makes the frosting easier to smooth.

Assemble and decorate the cake

If needed, use a serrated knife or cake leveler to trim any domed tops from the chilled cake layers.
Place the first cake layer on a cake board or serving stand. Add a small amount of buttercream to a piping bag and snip off the end. Pipe a thick buttercream dam around the edge of the layer, then spread a generous, even layer of buttercream inside it. The dam helps stabilize the layers.
Add the second cake layer and repeat with another dam and layer of buttercream. Place the final cake layer on top, flattest side facing up.
Apply a thin crumb coat of buttercream over the top and sides of the cake. Refrigerate for 20 to 30 minutes, or until the crumb coat feels firm.
Cover the chilled cake with the remaining blackberry buttercream. Smooth the top and sides with an offset spatula and cake scraper. Chill the finished cake until the frosting is firm.
Shortly before serving, arrange fresh blackberries and blueberries over the top of the cake. Nestle the meringue ghosts among the fruit.

Notes

I provide step-by-step photos below this recipe card if you need a visual guide.
Black cocoa: Look for it online or in specialty baking stores. It's the same cocoa that gives Oreo cookies their color. Since black cocoa has very little fat, I always pair it with dark cocoa so the cake stays moist and flavorful. If you can't find it, use 1 cup of Dutch-process or dark cocoa in total. The layers will be dark brown instead of black.
Coffee: Decaf coffee or hot water both work.
Superfine sugar: Pulse granulated sugar in a food processor for 30 to 60 seconds to make your own.
Room-temperature ingredients: Set out the eggs, egg whites, and sour cream about 1 hour ahead so the batter mixes smoothly.
Meringue and humidity: Meringue softens in damp air and in the fridge. Store the ghosts in an airtight container at room temperature and add them to the cake shortly before serving. See more tips for perfect meringue ghosts here.
The buttercream ring: There isn't a separate filling to hold in, but the thick piped ring around each layer helps keep the cake level and stable. See more buttercream tips here.
Leftover Reduction: Spoon any extra blackberry reduction over yogurt or oatmeal, or over ice cream.
Variations. This recipe is surprisingly flexible. See my suggested variations here.
Special Tools: Three 8-inch (20 cm) Round Cake Pans | Stand Mixer | Piping Bags | Large Round Piping Tip | Blender | Fine-Mesh Sieve | Offset Spatula | Cake Scraper | Cake Board or Stand | Serrated Knife or Cake Leveler

Storage and Make-Ahead Tips

Make ahead: Bake the meringue ghosts up to 1 week ahead and store airtight at room temperature. Make the reduction up to 5 days ahead and refrigerate it. Refrigerate the blackberry reduction for up to 5 days. Bake the cake layers up to 2 days ahead, wrap them tightly, and refrigerate. The buttercream keeps in the fridge for up to 1 week. Bring it to room temperature and re-whip before using.
Storage: Remove the ghosts, cover the cake, and refrigerate for up to 4 days. Let slices sit out for about 30 minutes before serving.
Meringue ghosts: For the best texture, remove the ghosts before refrigerating leftover cake. Store them separately in an airtight container at room temperature. Do not refrigerate the meringues, because they will absorb moisture and become sticky.
Blackberry reduction: Refrigerate it in an airtight container for up to 5 days.
Unfrosted cake layers: Wrap them tightly and store them at room temperature for 1 day. Or, freeze them for up to 2 months.
Freezing: Freeze unfrosted cake layers, wrapped in plastic wrap and foil, for up to 2 months. Thaw overnight in the fridge. Do not freeze the ghosts.
Serving leftovers: Let individual slices stand at room temperature for 20 to 30 minutes before serving so the cake and buttercream can soften.

Nutrition