Heat oven to 375°F. Place pie crust in 9-inch glass pie plate as directed on box for One-Crust Filled Pie.
In large bowl, mix brown sugar, flour, corn syrup, vanilla and eggs until well blended. Stir in pecans and butter. Pour filling into crust-lined plate.
Bake 40 to 50 minutes or until filling is puffed and pie is golden brown. Cool completely on cooling rack, about 2 hours, before serving. Store in refrigerator.