Preheat oven to 350°F (175°C). Line a 9x13 inch baking pan with parchment paper.
Make the crust: Whisk together flour and salt. Cut in butter and shortening until mixture resembles coarse crumbs. Gradually add ice water, mixing until dough just comes together. Press dough into prepared pan.
Make the filling: In a large bowl, whisk together corn syrup, brown sugar, granulated sugar, egg, and vanilla. Stir in pecans.
Pour filling over crust. Bake for 30-35 minutes, or until golden brown and set.
Let cool completely before cutting into bars.
Notes
Store leftover bars in an airtight container at room temperature for up to 3 days.