Line a 12-cup muffin tin with paper liners; set aside.
Using a small mixing bowl, add graham cracker crumbs, brown sugar and melted butter; stir until well combined.
Divide crust mixture evenly into lined muffin pan. (Tip: Pack mixture down into liners using a small flat-bottomed glass.)
Bake for 5 minutes. Remove from oven and set aside to cool.
For the Cheesecake
Using a countertop mixer, beat the cream cheese on medium speed until completely smooth (about 3 minutes).
Add sugar and flour; mix well, scraping down the sides of the bowl as needed.
Add eggs and egg yolk; mix until well combined.
Add the sour cream and vanilla extract; mix until well combined. (Tip: Use a spatula to scrape the sides and bottom of the bowl to ensure the filling is fully mixed.)
Pour batter evenly into muffin cups. (Note: The cheesecake batter will fill the liners nearly to the top.)
For the Pecan Pie Topping
Using a small saucepan, add brown sugar, heavy whipping cream, corn syrup, butter and salt.
Place over medium heat, stirring often, until mixture begins to boil. Once mixture begins to boil, let it boil for 1 minute, stirring constantly.
Remove saucepan from heat and stir in vanilla extract and pecans.
Carefully spoon pecan topping evenly into muffin cups (on top of cheesecake filling).
Bake for 18-22 minutes, or until centers of cheesecakes are just barely set. (Note: If you have an instant read thermometer, the temperature should be ~150°F.)
Let cheesecakes cool for 15 minutes and then transfer to freezer for 1 hour.
Remove paper liners from cheesecakes
Before serving, garnish tops of cheesecakes with freshly prepared whipped cream.