Two Cups Flour

0 Make the Ganache: Pour the cream into a small saucepan and bring to a simmer over medium heat. Remove from heat and stir in the chopped chocolate with a silicone spatula. Let the mixture sit for about 5 minutes, then stir until it looks like chocolate pudding. Let cool completely. 
1 Place the softened butter and vanilla into the bowl of a stand mixer fitted with the paddle and beat on medium for 2-3 minutes until fluffy. Add the powdered sugar, cocoa powder, and espresso powder, reduce to low and mix until blended.  It will look dry at first, but then come together into a thick frosting. Scrape the bottom and sides of the bowl to make sure all the butter is incorporated. 
2 Spoon in the cooled chocolate ganache and mix again on low until it looks like a spreadable smooth frosting. Scrape the bowl again, add the salt and give it a few more spins. 
3 Taste the frosting and adjust with more salt if needed to balance the sweetness.
4 Transfer frosting to piping bag or bowl and cover with plastic wrap until ready to use at room temperature the day of.
5 Store in an airtight container in the fridge for up to 1 week. Bring to room temperature and beat until smooth with handheld mixer to fluff before using.