In large bowl, beat powdered sugar, granulated sugar and butter with electric mixer on medium speed, scraping bowl occasionally, until blended. Beat in 1 egg at a time until blended. Beat 1 minute longer. On low speed, beat in flour mixture alternately with lemon juice, beginning and ending with flour mixture, until well blended. Stir in lemon peel and 1/2 cup pecans. Pour into pan.