MILE HIGH CHOCOLATE CAKE Recipe

Prepare & Preheat

Preheat the oven to 350°F (175°C). Grease and line three 8-inch round cake pans with parchment; lightly flour the sides (or use baking spray).

Dry Ingredients

In a large bowl, sift together the all-purpose flour, cocoa powder, baking powder, baking soda, and salt. Whisk in the granulated sugar until evenly combined.

Wet Ingredients

In a separate bowl, whisk together the buttermilk, whole milk, vegetable oil, eggs, and vanilla extract until smooth.

Combine Batter

With the mixer on low, gradually add the wet mixture to the dry ingredients just until combined. Add the hot brewed coffee and mix until smooth and homogenous. Scrape the bowl once to ensure no dry pockets remain. The batter will be thin — that's normal and helps produce tall, moist layers.

Bake

Divide the batter evenly among the three prepared pans (use a scale or measure by cups) and smooth the tops. Bake for 25–30 minutes, rotating the pans halfway through, until a toothpick inserted into the center comes out with moist crumbs (not wet batter) and the tops spring back when lightly pressed.

Cool

Allow the cakes to cool in the pans for 10 minutes, then run a knife around the edges and invert onto wire racks. Remove parchment and let cool completely (at least 1 hour) before filling and frosting. If cakes dome significantly, level with a serrated knife or cake leveler for even stacking.

Set up Bain-Marie

Combine the egg whites and granulated sugar in the heatproof bowl of a stand mixer (or a large metal bowl). Place the bowl over a simmering pot of water, making sure the bottom of the bowl does not touch the water. Whisk constantly until the sugar dissolves and the mixture reaches 160°F (71°C) on an instant-read thermometer, or until it feels smooth between your fingers (no detectable sugar grains).

Whip Meringue

Transfer the heated egg white-sugar mixture to the stand mixer fitted with the whisk attachment. Whip on medium-high speed until glossy, stiff peaks form and the bowl has cooled to near room temperature (this can take 8–12 minutes). This is your Swiss meringue base.

Add Butter

Switch to the paddle attachment. With the mixer on low, add the cold butter, a few cubes at a time, allowing each addition to incorporate before adding more. If the mixture appears broken or soupy, keep beating — temperature is often the issue; continue until smooth and silky. Once all butter is incorporated, add the sifted cocoa powder, vanilla extract, and salt. Beat on medium speed until the buttercream is uniform, light, and spreadable. Taste and adjust salt or cocoa if desired.

Optional Soak

If using, brush each cake layer lightly with simple syrup to add moisture and help keep the cake fresh. Use about 1–2 tablespoons per layer depending on dryness.

Stack & Fill

Place the first cake layer on a cake board or serving plate. Pipe or spread about 1 to 1 1/4 cups of chocolate buttercream evenly across the layer. Repeat with the second layer. Place the third layer on top.

Crumb Coat

Apply a thin layer of buttercream (about 1/2 cup) around the sides and over the top to seal in crumbs. Chill the cake in the refrigerator for 20–30 minutes until the crumb coat firms.

Final Frosting

Apply the remaining buttercream to create a smooth, high finish. Use an offset spatula and bench scraper for clean sides. For a 'mile high' appearance, pile extra buttercream on top in a peaked manner or build tall decorative swirls with a large round or star tip.

Garnish & Serve

Dust the top lightly with sifted cocoa powder and press dark chocolate shavings around the top edge or in the center as desired. Chill the cake for 10–15 minutes to set decorations, then bring to room temperature 30 minutes before serving for best texture.