Preheat your oven to 350°F (175°C).
In a mixing bowl, combine the softened butter, flour, and sugar. Mix until crumbly.
Press the mixture evenly into the bottom of a greased 9x13-inch baking dish.
Bake for 15 minutes or until lightly golden. Set aside.
In a medium saucepan, combine the sweetened condensed milk and butter.
Cook over medium heat, stirring constantly, until thickened and golden (about 10 minutes).
Remove from heat and stir in vanilla extract.
Pour the caramel filling over the baked crust and spread evenly.
Sprinkle chocolate chips evenly over the caramel.
Top with chopped pecans, pressing them gently into the caramel.
Return the baking dish to the oven and bake for an additional 15 minutes.
Remove and let cool completely before cutting into bars.