Preheat the oven to 350°F (175°C).
Mix flour, melted butter, and sugar; press into the bottom of a greased 9x13-inch pan.
Bake crust for 10-12 minutes or until lightly golden.
In a bowl, mix pecans and chocolate chips; set aside.
In another bowl, whisk brown sugar, corn syrup, eggs, and vanilla.
Pour pecan-chocolate mix over the crust and top with the syrup mixture.
Bake for 25-30 minutes. Let cool before slicing.