Heat oven to 375 degrees. Unroll dough into 2 long rectangles. Place in ungreased 13x9 inch pan; press dough over bottom, sealing perforations well. Sprinkle chips evenly over dough. Place marshmallow halves over chips, cut-side-down, in five rows of four.
Bake at 375 degrees for 10-12 minutes or until light golden brown. Cool about 15 minutes. Cut in squares around marshmallows.
Makes 20 bars.
TIP: For ease in cutting marshmallows, use kitchen scissors dipped in warm water.