1. Preheat oven to 350 degrees. 2. Grease a deep dish pie pan with cooking spray or butter. 3. Add cookies to the bowl of your food processor, and process until they resemble fine ground crumbs. Add melted butter, and pulse until well combined. 4. Press ground cookie butter mixture into pie dish. 5. Bake pie shell for 15 minutes. 6. While pie crust bakes, make the Thai tea custard. Add Thai tea mix to a medium heat proof mixing bowl. 7. Heat water in microwave or in a saucepan on high heat until boiling. Add to the bowl with the Thai tea powder, and whisk until fully combined. 8. In a separate bowl, whisk eggs and sweetened condensed milk until homogenous. 9. Add beaten eggs and pinch of salt to the bowl with the Thai tea liquid, and whisk until well combined. 10. Add 1 inches water to a roasting pan and and carefully place the baked crust/pie dish in the center. 11. Carefully pour Thai tea custard into the baked cookie crust shell. 12. Carefully transfer the roasting pan to the center rack of the oven. 13. Bake the custard pie for 45-55 minutes, or until a knife inserted in the center comes out clean. 14. Remove pie pan from water bath, cool to room temperature, and refrigerate until cold (about 2 hours, or up to overnight). 15. Serve cold, with whipped cream, if desired.