For the cake:
- ½ cup plus 1 tablespoon Dutch-process cocoa powder
- ½ cup plus 1 tablespoon hot water
- 2¼ cups all-purpose flour
- ¾ tsp. baking soda
- ¾ tsp. baking powder
- ½ tsp. salt
- 2 sticks plus 1 tablespoon unsalted butter, at room temperature
- 1 2/3 cups sugar
- 3 large eggs, at room temperature
- 1 tbsp. vanilla extract
- ¾ cup sour cream
For the filling:
- 1 cup (8 oz.) unsalted butter, at room temperature
- 2 cups confectioners’ sugar, sifted
- Pinch of salt
- 1 vanilla bean, split lengthwise (optional)
- 4 tsp. heavy cream
- 2 tsp. vanilla extract
For the glaze:
- ¾ cup heavy cream
- ¼ cup light corn syrup
- 8 oz. bittersweet chocolate, finely chopped
- ½ tsp. vanilla extract
step 1: Show Images
To make the cake, preheat the oven to 350˚ F. Grease and flour the edges of two 9-inch cake pans. Line the bottom of the pans with parchment rounds. In a small bowl, combine the cocoa powder and hot water and whisk until smooth. In another medium bowl combine the flour, baking soda, baking powder, and salt, and whisk to blend. Combine the butter and sugar in a medium saucepan set over medium heat. Cook, stirring occasionally, until the mixture is smooth and the butter is completely melted. Transfer the mixture to the bowl of an electric mixer and beat on medium-low speed until the mixture is cool, about 4-5 minutes. Add the eggs one at a time, mixing well after each addition and scraping down the sides of the bowl as needed. Blend in the vanilla and then the cocoa mixture until smooth. With the mixer on low speed, add the flour mixture in three additions alternating with the sour cream, beginning and ending with the dry ingredients and mixing each addition just until incorporated.
step 2: Show Images
Divide the batter between the prepared pans. Bake until a toothpick inserted in the center comes out clean, about 20-24 minutes, rotating the pans halfway through baking. Let cool in the pan about 15 minutes, then carefully remove to a wire rack to cool completely.
step 3: Show Images
To make the filling, place the butter in the bowl of an electric mixer fitted with the whisk attachment. Whip on medium-high speed until smooth, about 1 minute. Add the confectioners’ sugar to the bowl and mix on medium-low speed just until incorporated. Scrape the seeds from the vanilla bean pod (if using) into the bowl and add in the salt. Continue to beat on medium-high speed until smooth, about 1-2 minutes. Mix in the heavy cream and vanilla on low speed just until incorporated. Increase the mixer speed and whip on high speed until light and fluffy, scraping down the bowl as needed, about 4-5 minutes.
step 4: Show Images
Divide the frosting into two portions and tint one half black with gel food coloring. Place each portion into a separate pastry bag fitted with a plain round ½-inch tip. Start with a blob of black frosting in the center of one layer of cake. Pipe alternating circles of frosting over the cake layer working from the inside outward until the bottom cake layer is covered. Place the remaining cake layer on top. To make the glaze, combine the cream, corn syrup, and chocolate in a small saucepan. Heat over medium heat, stirring frequently, until smooth. Blend in the vanilla. Set aside for about 10-15 minutes, until slightly thickened. Spread the glaze over the cake and let set before proceeding.
step 5: Show Images
Use a pastry bag fitted with a small round tip (I used a Wilton #5) to pipe a not-quite-circle on top of the cake to form the boundaries for Jack’s head. Pipe several large blobs of white frosting within these borders and use an offset spatula to fill the white circle and smooth the surface as much as possible. Use a pastry bag fitted with a small round tip (such as Wilton #3 or 5) to pipe eyes, nostrils, and a mouth onto the head. Fill the eyes in a similar fashion as you did the head. Chill to set. Let come to room temperature before serving.