In a 3 quart mixing bowl combine flour, sugar and butter. Beat on medium speed, scraping sides of bowl often, until mixture resembles a fine meal (1 to 2 minutes). Stir in nuts. Press firmly in bottom of ungreased 9" square pan. Bake near bottom of oven at 350 for 18 to 22 minutes...or until very lightly golden on edges
Prepare filling: spread over crust. Return to oven for 20 to 30 minutes or until pecan mixture appears set and knife inserted 1" from edge comes out clean. Cool.