To a medium sized saucepan, whisk to combine maple syrup, tapioca starch, cocoa powder, and a generous pinch of sea salt until smooth (There should be no lumps). Stir in the coconut milk and whisk again to combine.
Cook the chocolate pudding over a medium high heat stirring constantly until it comes to a simmer. Once the pudding thickens, remove from heat. Stir in the vanilla and chocolate chips. Stir just until the chocolate melts and is smooth.
Pour the pudding into the prepared pie crust. Refrigerate the pie until the filling is firm, approx 4-6 hours. The pie and filling can be made 2 days in advance. If making ahead of time, make sure to cover the pie with plastic wrap once the filling has set.
Once your pie has set, you can layer with marshmallows and either use a small kitchen torch or your oven’s broiler.
If using a broiler: preheat broiler, and arrange marshmallows on top of the chilled pie. Broil until golden, watching closely to avoid burning, about 1 minute. (see notes for serving)