The Ultimate Recipe

Prepare and preheat

Center oven racks and preheat oven to 350°F (175°C). Grease and flour two 8-inch round cake pans (or line with parchment).

Whisk dry ingredients: In a large bowl, sift or whisk together 2.5 cups all-purpose flour, 1.75 cups granulated sugar, 2 tsp baking powder, 0.5 tsp baking soda, and 1 tsp fine salt until evenly combined.

Cream butter and sugar: In the bowl of a stand mixer fitted with the paddle attachment (or using a hand mixer), beat 0.75 cup softened unsalted butter on medium speed for 1 minute, then add half of the sugar mixture and beat until light and fluffy, about 2 minutes.

Add eggs and vanilla: Add the 3 large eggs one at a time, beating briefly after each addition. Mix in 2 tsp vanilla extract.

Alternate dry and wet: With the mixer on low, add the dry ingredients in three additions, alternating with the milk and buttermilk (start and end with dry ingredients): add one-third dry, then 0.5 cup whole milk + 0.5 cup buttermilk (combined quantities) divided as needed, repeat until batter is smooth. Scrape down the bowl as needed; mix until just combined—do not overmix.

Divide and bake: Divide batter evenly between prepared pans, smoothing tops. Bake for 25–30 minutes, or until a toothpick inserted in the center comes out clean and the cakes spring back lightly. Rotate pans halfway through if your oven bakes unevenly.

Cool: Let cakes cool in pans on a wire rack for 10 minutes, then run a knife around edges and invert onto racks to cool completely (about 1 hour). Level the tops if necessary for even stacking.

Warm cream: Place 8 oz chopped dark chocolate in a heatproof bowl. In a small saucepan, heat 1 cup heavy cream until it just begins to simmer (small bubbles at edge), then pour over chocolate.

Emulsify: Let sit 1 minute, then gently whisk from the center outward until smooth and glossy. Whisk in 1 tbsp unsalted butter and 1 tsp corn syrup (if using) until fully incorporated. Cover and let cool until thickened but still spreadable, about 20–30 minutes at room temperature; refrigerate briefly (5–10 minutes) if it becomes too soft.

Heat egg whites and sugar: In a heatproof bowl (preferably the bowl of a stand mixer), combine 4 large egg whites and 1.25 cups granulated sugar. Set the bowl over a pot of gently simmering water (double boiler), whisking constantly until the sugar is dissolved and the mixture reaches 160°F (71°C) or is warm and silky with no sugar graininess when rubbed between your fingers (about 3–4 minutes).

Whip to meringue: Transfer the bowl to the stand mixer fitted with the whisk attachment. Whip on medium-high until stiff, glossy peaks form and the bowl is cool to the touch (about 8–10 minutes).

Add butter: With the mixer on low, add softened unsalted butter 1 tbsp at a time until incorporated; once incorporated, increase speed to medium-high and continue whipping until smooth and silky, 3–5 minutes. If the buttercream curdles, keep whipping and it will come together; you can also chill briefly and rewhip. Add 2 tsp vanilla extract and 1/4 tsp fine salt; mix briefly to combine.

Prepare cake layers: Place one cake layer on a cake board or serving plate. If the cake dome has formed, trim the top to make it level.

Fill: Spread a thin crumb coat of Swiss meringue buttercream (reserve most for outside) on the first layer to lock crumbs. Pipe or dollop 3/4 to 1 cup of the chocolate ganache onto the center, spreading to within about 1/2 inch of the edge to create a ganache layer. Press a handful (about 1/4 cup) of the toasted chopped nuts into the ganache if you like crunch.

Stack: Place the second cake layer on top and press gently to level. Apply a generous coat of buttercream all over the top and sides of the cake, smoothing with an offset spatula. Thinly coat first (crumb coat) and chill the cake 15 minutes, then apply a final smooth layer of buttercream.

Decorate: Spoon remaining slightly warm (but not runny) ganache into the center of the top and nudge toward the edges so it drips slightly (for a drip effect) or simply spread it. Arrange fresh raspberries around the top and press remaining chopped toasted nuts around the bottom edge or scatter on top. Finish with chocolate shavings or curls and dust lightly with 2 tbs confectioners' sugar just before serving.

Chill and serve: Chill the assembled cake 30 minutes to set the ganache and buttercream. Bring to room temperature 20–30 minutes before slicing for best texture. Store refrigerated up to 4 days; bring to room temperature before serving.