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