Heat oven to 375°F. In large bowl, beat brown sugar, granulated sugar, butter and shortening with electric mixer on medium speed until light and fluffy, scraping bowl occasionally. Beat in vanilla and egg until well blended.
On low speed, beat in flour, baking soda and salt until dough forms. With spoon, stir in chocolate candies and nuts. Spread dough in ungreased 13x9-inch pan.
Bake 15 to 25 minutes or until light golden brown. Cool completely, about 30 minutes. Cut into 6 rows by 6 rows.