Instructions:

Make the Shortbread Base:

Preheat oven to 350°F (175°C). Line an 8×8 inch baking pan with parchment paper.
In a large bowl, cream together the softened butter and powdered sugar until light and fluffy.
Add the flour and salt and mix until just combined. Be careful not to overmix.
Press the dough evenly into the prepared baking pan.
Bake for 15-20 minutes, or until lightly golden brown. Let cool completely in the pan.
Make the Caramel Topping:

In a saucepan over medium heat, combine the brown sugar, butter, and heavy cream.
Cook and stir constantly until the sugar has dissolved and the mixture comes to a simmer.
Remove from heat and stir in the vanilla extract.
Spread the caramel evenly over the cooled shortbread crust.
Sprinkle with chopped pecans.
Chill and Cut:

Refrigerate the bars for at least 30 minutes, or until the caramel has set.
Cut into squares and enjoy!