Preheat your oven to 325°F (160°C)., Prepare your muffin pan or ramekins by lightly greasing them with cooking spray or butter., In a mixing bowl, combine the graham cracker crumbs, sugar, and melted butter. Mix until everything is evenly coated and resembles wet sand., Spoon about one tablespoon of this mixture into each muffin cup, pressing the crumbs down firmly., In another mixing bowl, beat the cream cheese until smooth and creamy using an electric mixer., Gradually add the sugar and continue mixing until well combined., Mix in the vanilla extract and salt, scraping down the sides of the bowl to ensure everything is incorporated., Add the eggs, one at a time, allowing each to fully incorporate before adding the next., Fold in the sour cream until the filling is smooth and creamy., Pour the cheesecake filling into each muffin cup, filling them about 3/4 full., Bake in the preheated oven for 20-25 minutes, or until the center is set but still slightly jiggly., Once baked, turn off the oven and leave the cheesecakes inside for an additional 30 minutes with the door slightly ajar., Remove from the oven and transfer to a wire rack to cool completely, then refrigerate for at least 4 hours (or overnight) before topping., Once chilled, sprinkle about one teaspoon of granulated sugar on top of each cheesecake layer., Using a kitchen torch, carefully caramelize the sugar by moving the flame over the sugar until it melts and turns a golden brown., Allow the caramelized topping to harden for a few minutes before serving.