Combine the gluten free graham style cracker crumbs with the salt and melted butter, mix well. Press evenly and firmly into a 9 inch pie plate.
Combine ¼ cup of heavy cream with the chocolate chips and microwave on high power for 2 minutes or until the cream is hot and the chocolate is almost melted. Stir vigorously until the mixture is smooth and glossy. (You can also place the cream and chocolate chips in a heatproof bowl and set over a pan of barely simmering water to melt the chocolate.) Pour the chocolate over the crust and spread into an even layer. Place in the freezer for 10 minutes.
Whip 1 ½ cups cream until stiff peaks form. In another mixing bowl, combine the Sunbutter with the remaining ½ cup cream, powdered sugar and vanilla. Beat until smooth and fluffy. Take a third of the whipped cream and stir it into the Sunbutter mixture, then fold in the rest of the cream until no longer streaky. Put the mixture into the pie plate on top of the chocolate layer and freeze for at least 2 hours.
Microwave the chocolate square for 15 seconds on medium power, then scrape the blade of a vegetable peeler along the edge to form into curls. Refrigerate the curls until ready to use. Scatter the chocolate curls over the top of the pie before serving.
To make it easier to cut the pie, take out of the freezer for 10 – 15 minutes before cutting.