Preheat oven to 350°F (175°C). Line a 9x13 inch baking pan with parchment paper.
In a medium bowl, cream together the butter and brown sugar until light and fluffy. Beat in the flour until just combined.
Press the dough into the prepared pan. Bake for 15 minutes.
Meanwhile, in a saucepan over medium heat, combine the corn syrup, sugar, and butter. Bring to a boil, stirring constantly. Cook for 5 minutes, or until the mixture reaches 245°F (118°C).
Remove from heat and stir in the pecans. Pour the caramel mixture over the baked crust.
Bake for another 10 minutes. Remove from oven and let cool completely.
Melt the chocolate chips. Spread evenly over the cooled caramel layer. Let set completely before cutting into bars.
Notes
Store leftover bars in an airtight container at room temperature.