Preheat your oven to 350 degrees Fahrenheit. Add cupcake liners to a muffin tin, and set aside.
In a microwave safe bowl, melt the 3 tbsp. butter by microwaving on 30 second increments.
In a medium mixing bowl, stir together graham cracker crumbs, brown sugar, and melted butter, until well combined.
Divide the crumb mixture between the lined muffin tin cups, and press the mixture into the bottom of each cup.
Bake at 350 for 5 minutes.
Meanwhile, in a large mixing bowl, use an electric mixer to mix together the cream cheese, pumpkin puree, sour cream, and granulated sugar.
Once combined, add the egg, cinnamon, pumpkin pie spice, cornstarch, and vanilla extract.
Mix again, until well combined.
Divide the cheesecake mixture between each of the muffin cups.
Bake at 350 for 20 minutes.
Allow the cheesecakes to cool, and then chill in the refrigerator for at least 2 hours.
Before serving, top with whipped cream and a sprinkle of pumpkin pie spice, if desired.