Spookilicious Mud Bars

1 cup plus 2 tablespoons all-purpose flour
1/2 teaspoon baking soda
1/2 teaspoon salt
3/4 cup packed brown sugar
1/2 cup butter, softened
1 teaspoon vanilla extract
1 large egg
2 cups (12-oz. pkg.) NESTL� TOLL HOUSE Semi-Sweet Chocolate Morsels, divided
1/2 cup chopped walnuts

PREHEAT oven to 375� F. Grease 9-inch-square baking pan.

COMBINE flour, baking soda and salt in small bowl. Beat sugar, butter and vanilla extract in large mixer bowl until creamy. Beat in egg; gradually beat in flour mixture. Stir in 1 1/4 cups morsels and nuts. Spread into prepared baking pan.

BAKE for 20 to 23 minutes. Remove pan to wire rack. Sprinkle with remaining morsels. Let stand for 5 minutes or until morsels are shiny; spread evenly. Cool in pan on wire rack; refrigerate for 5 to 10 minutes or until chocolate is set.

YIELD: 36 Bars