Prep your oven. Position a rack in the center of the oven and preheat the oven to 350°F. Line a half sheet pan with parchment paper.
Prep the pie crust. Place the frozen crust, still in its plate, in the center of the pan. Cover the crust with foil, making sure the crimped edges are completely covered and that there are no gaps between the foil and the crust. Fill with pie weights and spread them out so they are more concentrated around the edges of the crust.
Prebake the crust. Bake for 30 minutes. After 30 minutes, remove the sheet pan from the oven, keeping the oven on. Carefully lift out the pie weights and foil. Use a wooden skewer or a fork to poke holes all over the bottom and sides of the pie crust.Brush the bottom and sides of the pie crust (but not the crimped border) with a thin layer of the melted coconut oil. Bake, uncovered, for an additional 5 minutes. Set aside on a wire rack to cool slightly while you make the pumpkin pie filling. Make the pumpkin pie filling. In a medium bowl, whisk together the pumpkin puree, coconut milk, pumpkin pie spice, cinnamon, and salt. Whisk in the cornstarch and brown sugar. Slowly add the maple syrup and whisk to combine. Pour the mixture into the pre baked pie crust on the sheet pan.
Bake the assembled pumpkin pie. Bake for 45 to 50 minutes, or until the edges are set and the center of the pie just slightly jiggles. Cool on a wire rack.
Serve and store. Serve slightly warm or at room temperature with whipped cream. The pie can be kept at room temperature, under a cake dome or a large bowl turned upside down, for 1 day. After that, cover tightly in plastic wrap and refrigerate for 2 more days.