Chocolate Strawberry Cake

Place 1 cup low-fat buttermilk and 3 large eggs in a medium bowl. Let sit on the counter until room temperature.

Arrange a rack in the middle of the oven and heat the oven to 350°F. Lightly coat the bottoms of 3 (8-inch) round cake pans with cooking spray. Line the bottom of each pan with a parchment paper round. Lightly spray the sides and parchment-lined bottoms of each pan with cooking spray. Dust each pan with flour to prevent sticking. Tap out as much excess flour as possible so that the pans are coated with a very thin layer of flour.

(If you don’t have three pans, the cake can be baked in batches. Bake and cool the first batch of cakes as instructed. After removing the cakes from the pans to cool, wash and dry the pans and then prepare by spraying with cooking spray, lining the bottom with parchment, spraying once more, and dusting with flour. Pour the batter into the prepared pans and bake as instructed.)

Place 2 1/4 cups all-purpose flour and 1 cup natural unsweetened cocoa powder in a large bowl and whisk until combined and lump-free (if your cocoa is very lumpy, sift it into the bowl). Add 2 cups granulated sugar, 1 3/4 teaspoons baking powder, 1 teaspoon kosher salt, and 3/4 teaspoon baking soda. Whisk until combined.

Add 1 cup neutral oil and 1 1/2 teaspoons vanilla extract to the eggs and buttermilk and whisk until combined. Add 1/4 teaspoon instant espresso powder if using and 1 cup hot or warm freshly brewed, strong coffee. Stir to combine.

Add the buttermilk mixture to the flour mixture and whisk until just combined. (The batter will be thick and there may be some dry bits.) Add the coffee and whisk until smooth.

Divide the batter evenly between the cake pans (about 18 1/2 ounces each). Bake until the tops are rounded and a tester inserted into the center comes out clean, 23 to 25 minutes.

Place the pans on a wire rack and let the cakes cool slightly, about 10 minutes. Run a small offset spatula or paring knife around each cake to loosen. Flip each cake out and remove and discard the parchment. Flip again to be right-side up and place on the wire rack. Let cool completely, about 1 hour. Meanwhile, make the buttercream.

Place 5 sticks unsalted butter in the bowl of a stand mixer (or large bowl if using an electric hand mixer) and let sit at room temperature until softened. Meanwhile, make the strawberry purée.

Wash and hull 1 1/4 pounds fresh strawberries (about 4 cups). Place in the bowl of a standard food processor fitted with the blade attachment (work in 2 to 3 batches if you have a mini food processor). Add 5 teaspoons granulated sugar and a pinch of kosher salt. Process into a purée, about 2 minutes.

Transfer to a medium saucepan. Place over medium-high heat and bring to a gentle boil. Reduce the heat to maintain a steady simmer (slow bubbling is okay) and continue to cook, stirring often and making sure to scrape the sides, until darkened to a deep berry red color, reduced to a very thick purée, and the mixture clearly holds a line (without pooling back out) if the spatula is dragged across the bottom, 25 to 35 minutes.

Remove the saucepan from the heat. Finely grate the zest of 1/2 medium lemon until you have 1/2 teaspoon; add to the saucepan and stir to combine. Transfer to a small bowl or liquid measuring cup (you should have 3/4 to a scant 1 cup) and refrigerate until cooled to at least room temperature, about 1 hour.

Beat the butter with the paddle attachment on medium speed, scraping the bowl as needed, until smooth and creamy, 1 to 1 1/2 minutes. Add 3 heaping tablespoons of the strawberry purée and beat on medium speed just until incorporated.

Add 3 3/4 cups powdered sugar and add a pinch of kosher salt. Beat on low speed until the sugar and butter are mostly combined, about 30 seconds. Scrape the bowl down. Beat on medium speed until creamy and lightened, about 1 minute.

Reduce the mixer speed to low. Add 1/3 cup heavy cream and 1/2 teaspoon vanilla extract. Increase the speed to medium and continue to beat until fluffy, about 30 seconds.

Reduce the mixer speed to low. Add the remaining strawberry purée a little at a time and beat until fully combined. Taste and beat in up to 1/4 cup more powdered sugar if desired.

Using a serrated knife, trim the rounded tops from the cake layers. Place a serving platter or cake board on a cake turntable if you have one. Place a small dollop of buttercream on the center of the platter or board. Top with one of the cake layers.

Dollop 1 cup of the buttercream onto the cake layer. Spread into an even layer with an offset spatula, going all the way to the edges. Top with the second cake layer, then spread the same amount of buttercream on this layer. Top with the last cake layer with the flattest side facing up.

Using an offset spatula, spread and smooth a very thin layer of buttercream (called a crumb coat) over the top and sides of the cake, filling in any gaps between the layers as you go. You should be able to see the cake through the crumb coat. Refrigerate the cake until the crumb coat is set, 15 to 30 minutes.

Frost the entire cake with the remaining buttercream. Use an offset spatula and/or bench scraper (or alternatively another straight-edged tool) to smooth the buttercream.

Refrigerate the cake for at least 10 minutes to firm up the buttercream. This helps to reduce the risk of the warm ganache melting the buttercream. Note that the colder the cake, the faster the ganache will set. Meanwhile, make the ganache.

Finely chop 3 ounces bittersweet chocolate. Place in a small bowl and add a pinch of kosher salt. Bring 1/2 cup heavy cream to a steady simmer (steaming and bubbling along the edges) over medium heat in a very small saucepan; do not let it boil.

Immediately pour over the chocolate. Let sit for 1 minute. Stir until the chocolate is melted and the ganache is silky, smooth, and fluid. Let cool for 1 minute before using. The ganache should be warm and fluid, but not so hot that it will melt the buttercream.

For very controlled, defined drips: Use a piping bag filled with some of the ganache or small spoonfuls of ganache to create the chocolate drips around the perimeter of the cake). Fill the top of the cake with the remaining ganache. Using the back of a spoon or small offset spatula, gently smooth the top while pushing the ganache towards the edge to connect with the drips.

For a more organic-looking, blanket of ganache: Spoon all of the ganache on top of the cake and gently smooth with the back of the spoon or small offset spatula, coaxing some of the ganache towards the top edge to drip down.

Let the ganache set slightly, about 15 minutes. Decorate the top with fresh, whole and/or halved strawberries as desired.