Step 1

Line 8- or 9-inch-square baking pan with foil leaving an overhang on two sides.Spray foil with nonstick cooking spray.

Step 2

Heat 6 cups marshmallowsbutter and salt in largeheavy-duty saucepan over medium-low heatstirring frequentlyfor 5 to 10 minutesuntil smooth. Remove from heat. Add 1 cup morsels; stir until melted.

Step 3

Working quicklystir in graham cracker piecesremaining 2 cups marshmallows and 3/4 cup morsels. Spread mixture into prepared baking pan with greased spatulapressing down lightly.Cool for 2 hours or until set. Lift from pan; peel off foil. Cut into squares with serrated knife.