Chocolate Layer Cake with Raspberry Filling and Chocolate Ganache

• Preheat oven to 300° F (that is correct, 300°).
• Grease two 10" springform pans or round cake pans. Line bottoms with rounds of parchment paper. Grease the paper.

Make cake layers

• Place chocolate in large bowl. Cover with hot coffee. Let sit 4 to 5 minutes, then whisk until chocolate is smooth. If you plan to use an electric mixer, do this in the bowl of the mixer.
• Sift together flour, cocoa, baking soda, and baking powder in second large bowl.
• Into melted chocolate, whisk sugar, salt, oil, buttermilk, and vanilla until combined. This can be done by hand or in a electronic mixer.
• Whisk in eggs, one at a time, by hand or with mixer.
• Add flour mixture to chocolate. Whisk until smooth.

Bake cake layers

• Divide batter evenly between the two prepared pans.
• Bake layers in oven until toothpick inserted in center comes out clean, approx. 1 hour to 1 hour and 10 minutes.
• Cool layers in pans on racks for at least 10 minutes.
• Run a thin knife around the edges of the pans. Remove springforms, if using springform pans. Invert layers onto racks. Remove parchment paper. Cool layers completely.
• At this point, you can frost the cake immediately or you can wait until the next day. if waiting, wrap each layer well in plastic wrap and store at room temperature.

Prepare filling

• Puree raspberries in food processer or blender or with immersion blender.
• If you want to remove seeds (optional), press puree through a fine-mesh strainer with the back of a spoon.
• Mix together pureed raspberries, sugar, and cornstarch in small pot. Heat until mixture boils, stirring constantly. As mixture boils, it should thicken quickly.
• Remove from heat and let cool completely.

Fill cake

• Split each layer, so that you have four thin cake layers.
• Divide filling into three equal portions.
• Place first cake layer on serving plate. Spread first portion of filling over the top of the cake layer.
• Place second layer on top of first. Cover with second portion of filling.
• Place third layer on top of second. Cover with final portion of filling. Cover with final cake layer.
• If filling has oozed out from between the layers, smooth with small spatula or knife.

Prepare and apply ganache

• Combine cream, sugar, and corn syrup in 1½ or 2 quart saucepan. Bring to boil over moderately low heat, whisking until sugar is dissolved.
• Remove pan from heat. Add chocolate, whisking until chocolate has melted.
• Add butter and whisk until smooth.
• Transfer frosting to bowl and cool, stirring occasionally, until the ganache is the right thickness for spreading. To cool ganache quickly and evenly, place bowl with ganache in a bowl of ice water and stir until the ganache is the desired thickness.
• Spread ganache over top and sides of cake.