Fit the pie crust into an 8-inch pie dish and crimp the edges. Set it aside.
In a mixing bowl, combine the pumpkin puree, brown sugar, cinnamon, nutmeg, heavy cream, egg yolks, and vanilla extract. Stir until smooth.
Pour the pumpkin mixture into the prepared crust. Bake at 350°F for 35 minutes, or until the filling is set. Remove from the oven and let cool to room temperature.
In a clean bowl, beat the egg whites with an electric mixer until soft peaks form. Gradually add the granulated sugar and continue beating until stiff, glossy peaks form.
Spoon or pipe the meringue over the cooled pie in small ghost shapes. Return the pie to the oven and bake for 8 to 10 minutes, until the meringue turns light golden.