Step 1: Preheat and Prep
Let’s get chocolatey—crank your oven to 350°F and feel the kitchen hum with promise. Grease three 6-inch cake rounds with butter, dust with cocoa powder, and line bottoms with parchment (I love that slick prep!). Take a sec to breathe—this is gonna be a fudgy wonder, and you’re already on your way.

Step 2: Mix the Dry Goods
In a stand mixer bowl, toss in 1 ½ cups all-purpose flour, 1 ½ cups granulated sugar, ¾ cup cocoa powder, 1 ½ tsp baking soda, 1 tsp baking powder, and 1 tsp salt—mix ‘til blended (I love that cocoa puff!). This is the rich foundation—set the mixer aside (my kitchen’s buzzing with anticipation!).

Step 3: Whisk the Wet Mix
In a medium bowl, whisk 2 large eggs, ¼ cup vegetable oil, ¾ cup buttermilk, and 2 tsp vanilla extract—get it smooth (I grin at that creamy swirl!). Slowly pour in ¾ cup very hot water—whisk constantly (my heart races with that steam!). It’s the fudgy secret—ready to roll!

Step 4: Combine the Batter
Add the wet mix to the dry—beat on medium for 2-3 minutes (I love that thin batter dance!). Scrape the bowl—pour evenly into the pans (I’m drooling already!). Smooth the tops—it’s like painting chocolate dreams!

Step 5: Bake the Layers
Bake for 30-35 minutes—check ‘til a toothpick’s mostly clean (I watch with glee as they puff up dark!). Cool in pans on a rack 10 minutes—turn out and cool completely (that cocoa scent’s pure heaven!).

Step 6: Make the Honeycomb
Line a 9×13-inch sheet pan with a silicone mat or greased foil—set aside (I’m giddy for crunch!). In a large saucepan, mix 2 cups granulated sugar, ½ cup light corn syrup, and ⅓ cup water—stir ‘til dissolved, then stop (my kitchen smells like candy!). Brush the sides with a wet pastry brush—boil on high ‘til 300°F on a candy thermometer, about 10 minutes (my heart’s pounding!). Remove from heat—sprinkle 1 tbsp sifted baking soda and whisk fast, 5 seconds max (I love that foam explosion!). Pour into the pan—cool 1-2 hours (I sneak peeks ‘til it’s ready!). Break into shards—chop some small for layers (my crunch dreams come true!).

Step 7: Whip the Frosting
Whisk 3 cups sifted powdered sugar, 1 cup sifted regular cocoa, and 3 tbsp black cocoa in a bowl—set aside (I love that dark mix!). Beat 1 ½ cups room-temp unsalted butter ‘til smooth—add sugar mix 1 cup at a time (I grin at that fluff!). Mix in 3 oz melted, cooled dark chocolate—add 1-3 tbsp heavy cream ‘til creamy (I used 3!). Beat on high 5 minutes—silky fudge heaven (I sneak a taste—it’s bliss!).

Step 8: Assemble the Cake
Place one cooled layer on a stand—spread ⅔ cup frosting, sprinkle crushed honeycomb (I feel like a cake artist!). Repeat with the next two layers—crumb coat and chill 30 minutes (my heart races with each stack!). Frost the sides and top rustic-style—shard honeycomb on top (that first bite’s pure magic, and you made it happen!). Store covered—I sneak bites ‘til it’s gone!