Prepare the Crust:
In a bowl, combine chocolate graham cracker crumbs, melted butter, and sugar.
Press the mixture firmly into the base of mini cheesecake molds or a muffin tin lined with parchment cups.
Chill in the refrigerator for 15 minutes.
Make the Coffee Cheesecake Filling:
In a mixing bowl, beat cream cheese, powdered sugar, and vanilla extract until smooth.
Stir in the dissolved espresso until well combined.
Gently fold in whipped heavy cream until the mixture is light and fluffy.
Spoon the filling over the crusts, smoothing the tops.
Refrigerate for at least 4 hours or until set.
Prepare the Ganache:
Heat heavy cream in a small saucepan until hot but not boiling.
Pour over chocolate chips and let sit for a minute. Stir until smooth.
Allow to cool slightly, then pour over the chilled cheesecakes.
Garnish & Serve:
Sprinkle crushed pistachios on top and dust with cocoa powder if desired.
Chill for another 30 minutes before serving.