Let’s create this stunning Dark Chocolate Honeycomb Cake:

1. Make the Chocolate Cake Layers:

Preheat oven to 350°F (175°C). Grease three 6-inch round cake pans. Dust with cocoa powder and line the bottoms with parchment paper.

Place flour, sugar, cocoa powder, baking soda, baking powder, and salt into the bowl of a stand mixer (paddle attachment). Mix on low speed until well combined.

In a medium bowl, whisk together eggs, oil, buttermilk, and vanilla extract.

Very slowly pour the very hot water into the wet ingredients while whisking constantly.

With the mixer on low speed, add the wet ingredients to the dry ingredients. Mix on medium speed for 2-3 minutes until smooth. The batter will be very thin.

Pour the batter evenly into the three prepared pans.

Bake for approximately 30-35 minutes, or until a toothpick inserted into the center comes out mostly clean (a few moist crumbs are okay).

Place the cakes on a wire rack to cool in the pans for 10 minutes. Then turn the cakes out onto the wire rack, remove parchment, and let them cool completely.

2. Make the Honeycomb Candy:

Line a quarter sheet pan (9” x 13”) with a silicone baking mat or well-greased heavy-duty aluminum foil.

Place the granulated sugar, light corn syrup, and water into a large, heavy-bottomed saucepan. Stir well to combine and ensure the sugar starts to dissolve. Do not stir from this point forward.

Wash down the sides of the pot with a pastry brush dipped in water to remove any sugar crystals.

Bring the mixture to a boil over high heat. Clip on a candy thermometer. Cook, without stirring, until the temperature reaches exactly 300°F (150°C) – the hard crack stage. This will take about 10 minutes, watch carefully!

Immediately remove the saucepan from the heat. Sprinkle the sifted baking soda all over the top. Quickly whisk it in – the mixture will foam up dramatically (growing about 4 times in size!) and turn golden. Do not over-whisk (max 5 seconds), just enough to incorporate the soda, or it will deflate.

Instantly pour the foaming mixture into the prepared lined pan. Do not spread it. Allow it to cool completely and harden at room temperature (1-2 hours).

Once cooled and hard, use the tip of a knife or gently break the honeycomb into large shards for decoration. Chop up some of the honeycomb into smaller, pea-sized pieces to add between the cake layers. Store extra honeycomb in an airtight container at room temperature, separated by parchment paper (humidity is its enemy!).

3. Make the Chocolate Fudge Frosting:

In a medium bowl, whisk the sifted powdered sugar and sifted cocoa powder(s) together to combine.

In the bowl of a stand mixer fitted with the paddle attachment, beat the room temperature butter on medium speed until smooth and creamy, about 1 minute.  

With the mixer on low speed, add the sugar/cocoa mixture 1 cup at a time, mixing well after each addition. Scrape the bowl.

Beat in the melted and cooled dark chocolate until combined.

Add heavy cream, 1 tablespoon at a time, beating on medium speed, until the frosting reaches your desired smooth and spreadable consistency (you might need 1-3 tablespoons).

Increase the speed to high and continue beating until the frosting is very smooth and fluffy, approximately 5 minutes.

4. Assemble the Cake:

Place one cooled chocolate cake layer onto a cake stand or serving plate.

Top with approximately ⅔ cup of the fudge buttercream and spread it evenly. Sprinkle some of the crushed honeycomb pieces over the frosting.

Place the second cake layer on top. Repeat with another ⅔ cup frosting and more crushed honeycomb.

Place the third cake layer on top. Apply a thin “crumb coat” of frosting over the entire cake (top and sides) to trap any loose crumbs. Refrigerate for 30 minutes to firm up the crumb coat.

Frost the cake sides and top smoothly or with a decorative rustic pattern using the remaining frosting.

5. Decorate and Serve:

Carefully arrange the larger honeycomb shards along the top edge or sides of the cake as desired for a dramatic effect.

Serve the cake at room temperature. Enjoy!