01 - Preheat oven to 325°F (165°C) and line a 12-cup muffin tin with paper liners.
02 - In a medium mixing bowl, combine graham cracker crumbs, granulated sugar, and melted unsalted butter. Mix until the crumbs are evenly moistened, then divide the mixture evenly among the prepared liners and press firmly to form an even crust base.
03 - Beat softened cream cheese and granulated sugar together until smooth and creamy. Add the egg, vanilla extract, and sour cream. Mix gently until combined, ensuring not to overmix.
04 - Spoon cheesecake filling evenly over each prepared crust. Bake in the preheated oven for 16 to 18 minutes, until the centers are just set. Remove from the oven and allow to cool in the pan at room temperature for 30 minutes. Refrigerate for at least 1 hour to set completely.
05 - While cheesecakes chill, combine brown sugar, unsalted butter, heavy cream, and salt in a small saucepan over medium heat. Stir constantly and bring to a simmer, allowing the mixture to thicken for about 3 to 4 minutes. Remove from the heat, stir in chopped pecans and vanilla extract, and let cool slightly.
06 - Once cheesecakes are thoroughly chilled, spoon pecan topping generously over each one. Refrigerate for an additional 15 to 20 minutes, then serve chilled.