Preheat the oven to 175°C (350°F).
In a large bowl, whisk together the sugar, flour, cocoa powder, baking powder, baking soda, and salt.
In a separate bowl, whisk together the eggs, buttermilk, vanilla extract, and neutral oil.
Pour the wet ingredients into the dry ingredients and mix until just combined.
Slowly pour in the hot coffee and mix until the batter is smooth. The batter will be thin.
Fold in the chocolate chips, if using.
Bake until a toothpick inserted into the center comes out with a few moist crumbs. About 20-25 minutes
Heat the heavy cream until it is just beginning to simmer. Do not let it boil.
Pour the hot cream over the chocolate chips.
Let it sit for 2–3 minutes, then stir until smooth and glossy.
