Grease a 9-inch deep-dish pie plate or springform pan (or even a simple round 9-inch cake pan with high sides), and set it aside.
Prepare and parbake the crust according to the recipe instructions (or prepare the cookie crust according to the instructions in the ingredients list). Allow the crust to cool briefly while you prepare the filling.
In a food processor or blender, place the ricotta cheese, mascarpone cheese, eggs, vanilla, sugar and salt, and pulse or blend until very smooth.
Add the miniature chocolate chips, and mix by hand until evenly distributed throughout.
Pour the filling into the prepared pie crust, and smooth into an even layer.
Place the pie plate or pan in a larger, heat safe pan like a roasting pan. Pull out the bottom rack of the preheated oven and place the pan on the rack.
Pour lukewarm water into the roasting pan until reaches about 1/2-way up the sides of the pie plate/pan. Push the rack carefully back into place, and close the oven.
Allow the pie to bake for about 50 minutes, or until the filling is mostly set. The center of the filling should shake in a controlled (not loose) way when shaken gently.
Remove the pie from the water bath and return just the pie to the oven. Turn off the oven and leave the oven door open about 2 inches.
Allow the pie to sit in the oven for 10 minutes, then remove and allow to cool to room temperature.
Cover and place in the refrigerator to chill until firm (at least an hour, and up to 3 days). Drizzle with melted chocolate before slicing and serving, chilled.
Notes
For an alternative crust.In place of the pastry crust, make a cookie crust. In a large bowl, mix 1 1/2 cups (225 g) gluten free crunchy cookie crumbs and 6 tablespoons (84 g) unsalted butter, melted until well-combined.Press the mixture into the bottom and up the sides of a 9-inch springform pan or greased deep-dish pie plate.Place the pie plate in the freezer for about 5 minutes or until firm before proceeding with the rest of the recipe.