Separate crescent dough into two large rectangles. Place in ungreased 15 x 10 inch jelly roll pan. Gently press dough to cover bottom of pan; seal perforations.
In small saucepan, combine brown sugar and margarine; boil 1 minute. Pour evenly over dough. Sprinkle with nuts.
Bake at 375° for 14-18 minutes until golden brown.
Remove from oven; immediately sprinkle with chocolate pieces. Slightly swirl pieces as they melt, leaving some pieces partially melted or whole. Leave a mottled appearance.
Cool and cut into bars.
Recipe submitted by Sue on 12/21/99