Chocolate Ganache Cake

Ingredients

FOR THE CAKE

• Nonstick baking spray
• 3/4 c. all-purpose flour
• 1 c. granulated sugar
• 1/3 c. unsweetened cocoa powder
• 1 tsp. baking soda
• 1/2 tsp. baking powder
• 3/4 tsp. salt
• 1/2 c. buttermilk 
• 1/4 c. canola oil
• 1 large egg, at room temperature
• 1 1/2 tsp. vanilla extract
• 1/2 c. freshly brewed strong coffee 

FOR THE CHOCOLATE GANACHE

• 1 c. bittersweet chocolate chips
• 1 tbsp. salted butter
• 1 c. heavy cream
• 1 1/2 tbsp. light corn syrup

FOR THE PEANUT BUTTER GANACHE SWIRL (OPTIONAL)

• 1/2 c. peanut butter chips
• 1 tbsp. salted butter

Directions

1. Preheat the oven to 350°. Spray a 9-inch round cake pan with nonstick baking spray. Line the bottom of the pan with parchment paper and spray with nonstick baking spray. Set the pan aside.
2. Sift the flour, sugar, cocoa powder, baking soda, baking powder, and salt in a large bowl; whisk to combine. In a separate large bowl, whisk together the buttermilk, oil, egg and vanilla. Gradually add the flour mixture to the buttermilk mixture, and whisk until well combined. Add the coffee and whisk just until evenly incorporated.
3. Transfer the batter to the prepared pan and bake for 28 to 32 minutes, until a toothpick comes out clean. Let the cake cool in the pan for 15 minutes. Invert onto a cooling rack to cool completely, 1 hour.
4. For the chocolate ganache: In a 4-cup heat-proof liquid measuring cup with a spout, combine the chocolate chips and 1 tablespoon butter. In a small saucepan, bring the cream and light corn syrup to low simmer over medium-low heat. Pour the cream mixture over the chocolate mixture and let it stand for 2 minutes. Stir until very smooth. Set aside until cooled slightly, but still pourable (about 105°), 2 to 5 minutes.
5. While chocolate ganache is cooling, set the cake, still on the wire rack, in a rimmed baking sheet. 
6. Once the ganache has cooled slightly, pour it over the cake, making sure to completely cover the top and sides, letting any excess run off into the rimmed baking sheet. Smooth the top of the cake using a large offset spatula.7Immediately transfer the cake to the refrigerator to harden the ganache, 30 minutes. Using 2 large spatulas, carefully transfer the cake to a serving platter. Serve slightly chilled or at room temperature.
7. For the peanut butter ganache swirl (optional): While the chocolate ganache is cooling in Step 4, combine the peanut butter chips and butter in a small microwavable bowl. Microwave on high until mixture is melted and smooth, 30 seconds, stopping to stir after 15 seconds. Transfer peanut butter mixture to a small Ziploc bag with a 1/4-inch hole cut in the corner. Immediately after covering the cake with warm ganache in Step 6, pipe 6 equally spaced lines of the peanut butter mixture across the top of the cake. Using a paring knife or skewer, drag the tip through the peanut butter and ganache in 7 evenly spaced lines perpendicular to the piped peanut butter, alternating the direction of each line. Proceed with Step 7 and cool cake as directed.