Step 1

Start by making the cake: Preheat the oven to 375°F. Spray a half sheet pan (about 11×17”) with nonstick cooking spray, line the bottom with parchment paper and spray the parchment paper. Coat the sides and bottom with flour, tapping out any excess.

Step 2

Place the eggs in the bowl of a stand mixer fitted with the whisk attachment. Whisk the eggs on medium until they are broken up, then add the vanilla. With the mixer still running, add the granulated sugar. Increase the speed to medium-high and beat till the mixture is thick and pale.

Step 3

Using a rubber spatula, fold in half the flour and all of the kosher salt. Add the melted butter and fold again. Finish with the remaining flour. Pour the batter into your prepared pan and use an angled spatula to spread evenly.

Step 4

Bake for 8-10 minutes, rotating the pan halfway through. The cake is done when light golden brown and springs back when lightly touched. Place on a wire rack and cool completely in the pan.

Step 5

While the cake is cooling, make the coffee buttercream: Whisk the coffee and espresso powder in a small bowl until the espresso powder is fully dissolved. Set aside.

Step 6

Beat the butter and confectioner’s sugar on low until the ingredients are completely incorporated, then raise the speed to medium-high and beat till light and fluffy. Scrape down the sides, add the coffee mixture and beat again till fully incorporated. Transfer the buttercream to a bowl.

Step 7

To assemble the cake, generously dust the top of the cake (still in the pan) with confectioner’s sugar. Use a small knife to loosen the cake from the sides of the pan. Place a piece of parchment paper on top of the cake and place a cutting board on top of the parchment paper. Holding the pan and board together, flip over so the board is now on the bottom. Gently remove the pan from the cake and peel off the parchment paper.

Step 8

Using a large sharp knife and a pressing (versus a slicing motion), trim the edges of the cake. Once trimmed, cut the cake into eight pieces; set one aside.

Step 9

Place one of the layers onto a parchment-lined work surface and top with about 1/3 cup of the buttercream. Use a small angled spatula to spread evenly. Continue layering with the remaining six layers, and top with all of the buttercream that remains in the bowl. Use your spatula to spread a thin layer of buttercream on the sides of the cake, and level the top as evenly as possible. Place in the fridge to set, 2 hours or up to overnight.

Step 10

Make the ganache: Place the chocolate in a medium heatproof bowl. Heat the cream in a small saucepan till small bubbles appear around the edges. Immediately pour over the chopped chocolate and leave undisturbed for 3 minutes. Whisk till the ganache is smooth and emulsified. Let cool till no longer hot but still pourable.

Step 11

Use a large wide knife or spatula to carefully transfer the chilled cake to a wire rack set over a parchment lined baking sheet. Pour the ganache slowly over the top of the cake, using a small angled spatula to spread it over the sides. Scoop any ganache from the parchment paper and return to the bowl. Return to the fridge to set for 2 hours or up to overnight. At this point you can serve the cake or pour another layer of ganache over, for a thicker icing. The ganache may have thickened by this point; to make it pourable again place the bowl over a saucepan of barely simmering water, stirring constantly. Once the ganache is smooth and glossy again remove it from the heat and proceed with the second coat. Return to the fridge to set.

Step 12

Transfer the cake to a plate or board, cut into slices and serve.