Pre-heat oven to 325°F.
Place the dark chocolate in a heat-safe bowl. Heat ¼ cup of the heavy cream over medium heat until is just begins to simmer.
Pour the cream over the chocolate and let stand for 30 to 60 seconds. Whisk the chocolate until melted and smooth.
Pour the chocolate ganache into the blind baked pie crust and spread smooth with an offset spatula. Set aside to cool while you prepare the pumpkin pie filling.
In a large bowl, whisk together the pumpkin puree, eggs, egg yolk, and remaining 1 cup of cream until well combined.
In a separate bowl, stir together the brown sugar, spices and salt. Whisk the sugar/spice mixture into the pumpkin mixture. Pour the filling on top of the chocolate layer.
Bake the pie until the edge of the filling is slightly puffed and set, but the center still wobbles when you shimmy the pan, 55 to 70 minutes.
Turn off the oven, prop the door open with a wooden spoon, and allow the pie to cool in the warm oven for 30 minutes (to help prevent cracks). Completely cool the pie at room temperature. Loosely cover the cooled pie with plastic wrap and store in the refrigerator up to 2 days before serving.
To make the meringue, place the sugar, water, and corn syrup in a saucepan and bring to a boil over high heat. Cook the sugar syrup until it reaches 238°F on a candy thermometer. Meanwhile, place the egg whites and cream of tartar in the bowl of stand mixer fitted with the whisk attachment. Beat the egg whites on medium-high until soft peaks. Stop the mixer.
When the sugar syrup reaches 238°F, promptly remove it from the heat. Turn the mixer back on high speed. Carefully and slowly pour the sugar syrup down the side of the mixer bowl and into the whipping whites. Continue to whisk on high speed for about 8 to 10 minutes, or until thick, glossy, stiff peaks form. Mix in the vanilla and use immediately.
If the pie had been refrigerated, pat the top with a paper towel to remove any condensation (don’t skip this or the meringue may weep and slide around when sliced). Swirl on the meringue and toast with a kitchen torch. Decorate with chocolate chips by pressing the tops into the toasted meringue. Gently go back over the chocolate with the torch to slightly melt (if desired).