Devil's Food Cake

Ingredients

• For the cake:
• 12 ounces unsalted butter
• 12 ounces brewed black coffee, or black tea such as Assam
• 3 ounces Dutch-process cocoa powder, such as Cacao Barry Extra Brute
• 6 ounces finely chopped dark chocolate, roughly 72%
• 16 ounces light brown sugar
• 1/2 ounce vanilla extract
• 1 teaspoon Diamond Crystal kosher salt; for table salt, use about half as much by volume or the same weight
• 6 large eggs, straight from the fridge
• 3 large egg yolks, straight from the fridge
• 9 ounces all-purpose flour, such as Gold Medal
• 1 tablespoon baking soda
• To Finish:
• 1 recipe Chocolate Swiss Buttercream or other frosting
• 5 ounces finely ground Oreo wafer crumbs, store-bought or homemade, optional

Directions

1. Getting ready: Move an oven rack to the lower-middle spot and heat the oven to 350 degrees F (180 degrees C). Fit three 8- by 3-inch anodized aluminum pans with parchment, then coat them with pan spray. The cakes may also be baked in 2-inch-deep pans, but expect them to round more on top and climb a little less.
2. For the cake: In a 5-quart stainless steel pot or saucier, warm the butter with the coffee or tea over low heat until the butter has melted. Take the pot off the heat, then stir in the cocoa and chocolate. Add the brown sugar, vanilla, and salt, and mix again. Whisk in the eggs and yolks, then sift the flour and baking soda into the pot. Whisk until the batter is completely combined.
3. Portion the batter into the prepared pans, using about 23 ounces for each one. If all three pans are not available, the extra batter can sit at room temperature for up to 90 minutes, though the finished layer will not rise quite as much. Bake for about 30 minutes, until the cakes feel set but a gentle press still marks the puffed surface; a toothpick pushed into the middle should come out with a few crumbs clinging to it.
4. Leave the cakes in their pans to cool for 1 hour. Slide a butter knife around the sides to release them, turn them out onto a wire rack, remove the parchment, and flip the layers back upright. While they cool, make the buttercream.
5. For the crumb coat: Use a serrated knife to even out the cake layers, saving the trimmings for snacking. Set 1 layer on a sturdy cast iron turntable. If desired, place a waxed cardboard cake round underneath first, anchoring it to the turntable with a small piece of damp paper towel. Spread exactly 1 cup buttercream over the top with an offset spatula, taking it all the way to the edges. Add the second and third layers the same way, then use another cup of buttercream to cover the sides as neatly as you can. If you want more frosting, add a second coat. Chill the cake for about 30 minutes, until the buttercream is firm. If desired, cover the outside of the chilled cake with chocolate cookie crumbs.
6. Bring the cake back to cool room temperature before slicing. Covered with a cake dome or an upside-down pot, the frosted cake will hold for 24 hours at cool room temperature. Once sliced, wrap the remaining pieces individually and keep them at cool room temperature for up to 3 days more.