PREHEAT oven to 350° F. Line 9-inch-square baking pan with aluminum foil; grease.
BREAK dough along pre-scored lines; place in large bowl. Add 1/2 cup morsels, oats and 1 cup peanut brittle; combine well. Press onto bottom of prepared pan.
BAKE for 18 to 20 minutes or until golden brown and puffed. Cool completely in pan on wire rack.
MELT remaining morsels and peanut butter in small saucepan over medium-low heat, stirring constantly, until chocolate is melted. Spread over cool bars. Sprinkle with nuts. Let stand until chocolate just begins to set before cutting into bars.