01 -
Preheat oven to 350°F (177°C). Grease a 6-inch round cake pan, line with parchment paper, then grease the paper.
02 -
Whisk together flour, cocoa powder, baking soda, espresso powder, and salt in a large bowl.
03 -
In a medium bowl, whisk oil, sugar, egg, vanilla, and buttermilk until combined. Pour into dry ingredients and whisk until smooth.
04 -
Pour batter into prepared pan. Bake 27-30 minutes until a toothpick comes out clean. Cool completely on a wire rack.
05 -
Pour heated cream over chopped chocolate. Let sit 2-3 minutes, then stir until smooth. Cool 30-60 minutes until thickened.
06 -
Spread or pipe ganache on cooled cake. Add optional garnishes like raspberries, mint, or sprinkles.