in a medium bowl, add in chopped chocolate and salt
heat heavy cream in a pan over medium heat until it's just steaming
pour cream over the chocolate and salt, let sit for a minute, then stir until glossy and smooth
stir in vanilla and espresso powder
let mixture cool for ~5 minutes until it thickens slightly, then spread over waffles (note: you'll have more ganache than you need for 6 waffles, but i like having extra for generous spreading, drizzling, or spooning straight from the bowl)
top with marshmallows and give it a torch until toasty, or broil the waffles on high for ~1-2 minutes until marshmallows are golden brown
optionally: finish with graham cracker dust