Chocolate Oat Squares

I got this one from a former co-worker who got it from Taste Of Home.

1 C plus 2 Tbsp butter or margarine, softened, divided
2 C packed brown sugar
2 eggs
4 tsp vanilla extract, divided
3 C quick-cooking oats
2 1/2 C all-purpose flour
1 1/2 tsp salt, divided
1 tsp baking soda
1 (14oz) can sweetened condensed milk
2 C (12oz) semisweet chocolate chips
1 C chopped walnuts

In a mixing bowl, cream 1 cup butter and brown sugar. Beat in eggs and 2 teaspoons vanilla. Combie the oats, flour, 1 teaspoon salt and baking soda; stir into creamed mixture. Press two-thirds of oat mixture into a greased 15x10x1" baking pan. In a saucepan, combine milk, chocolate chips and remaining butter and salt. Cook and stir over low heat until chocolate is melted. Remove from heat; stir in walnuts and remianing vanilla. Spread over the crust. Sprinkle with remaining oat mixture. Bake at 350 for 25 minutes or until golden brown. Cool; cut into squares.