Preheat oven to 350 degrees F. Line a 13x9x2-inch baking pan with foil, leaving about 1 inch of foil extending over the ends of pan; set aside. In a medium mixing bowl beat flour, 1/2 cup brown sugar, and the 1/2 cup butter with an electric mixer on medium speed until mixture resembles fine crumbs. Press mixture evenly into the bottom of the prepared pan.

Bake in the preheated oven about 15 minutes or until light brown. Remove from oven. Sprinkle nuts, baking bars, and milk chocolate pieces over hot crust.

In a small saucepan cook and stir the 3/4 cup butter and 1/2 cup brown sugar over medium heat until bubbly. Cook and stir for 1 minute more. Pour sugar mixture evenly over bars. Bake about 15 minutes more or until just bubbly around edges. Cool in pan on a wire rack. Remove bars from pan, using the overlapping foil to lift bars. Place on cutting board; cut into bars. Makes 36 bars.