Preheat oven to 350°F. Place pie crust in pan and crimp edges (if homemade), prick the bottom with a fork, Place the pie crust on a cookie sheet. Bake for 10 minutes. The crust will be lightly brown.
Spread chocolate chips and pecans evenly in the bottom of the pie crust.
Mix butter, sugar, flour, eggs, and vanilla until smooth. Pour over chips and nuts. Spread evenly. Bake 35 minutes. The top should be brown but the center will remain slightly 'jiggly'. It will set after it cools.
Allow the pie to cool for 15 minutes before cutting.