For the crust: In a large bowl, cream butter and sugar. Add flour and salt. Beat at medium speed until mixture resembles fine crumbs. Press firmly into a 15x10 inch greased pan. Bake for 25 minutes or until golden brown.
For the filling: In a large bowl, beat the eggs, corn syrup, sugar, melted butter, and vanilla until well blended. Stir in pecans and pour over crust. Spread evenly.
Bake for 25 minutes or until filling is firm around the edges. Cool completely before cutting into bars.