Preheat the oven and line a rectangular pan with parchment paper.
Whisk the dry ingredients together in one bowl.
In another bowl, mix the eggs, sugars, oil, buttermilk, and vanilla until smooth.
Add the dry ingredients, then stir in the hot coffee to make a thin batter.
Bake until set, then cool the cake completely before layering.
Beat the cream cheese with powdered sugar, then fold in whipped cream and melted white chocolate.
Spread the cream mixture over the cooled cake and chill until firm.
Heat the heavy cream and pour it over the chocolate chips to make ganache.
Pour the ganache on top, finish with curls, chill again, and slice into bars.
