Place an oven rack in the center of the oven, then preheat to 375°F. Place the pie crusts on a sheet pan, leaving them in their tins. Bake 10 to 12 minutes, or until lightly browned and cooked through. Transfer to a cooling rack and let stand about 10 minutes, or until room temperature.  

Once the crusts have cooled about 5 minutes, in a bowl, combine the chocolate chips, a pinch of salt, and 2 tablespoons of water. Working in 30 second increments, microwave on high, stirring in between, until melted and smooth (or melt in a small pot on the stove, then transfer to a bowl). Add the espresso pastry cream; whisk to combine. Divide the filling between the cooled pie crusts and spread into an even layer. Refrigerate about 2 hours (or overnight), or until set and chilled.

While the pies set, roughly chop the pistachios. Line a plate with parchment paper (or lightly grease). In a small nonstick pan, heat a drizzle of olive oil on medium-high until hot. Add the chopped pistachios. Cook, stirring frequently, 1 to 2 minutes, or until lightly toasted. Add the maple syrup. Cook, stirring constantly, 30 seconds to 1 minute, or until the pistachios are coated. Transfer to the plate; spread into an even layer to avoid sticking. Immediately season with salt. Set aside to cool. (If storing overnight, store in an airtight container with the parchment.)

(If you refrigerated the pie overnight, remove from the fridge at least 1 hour before serving to bring to room temperature.) When ready to serve, place the cream (shaking the packet before opening) in a medium bowl (or the bowl of stand mixer). Whisk constantly, 2 to 3 minutes (if using a hand mixer or stand mixer, beat on high about 2 minutes), or until stiff peaks form. Serve the set pies topped with the whipped cream and candied pistachios. Enjoy!