Line a 13x9 in. pan with foil and grease with butter; set aside.

In a heavy saucepan, combine sugar, heavy cream, and butter. Cook and stir over low heat until sugar is dissolved (this is a key step)

Once sugar is dissolved, bring to a boil over medium heat; cook & stir for 4 minutes.

Remove from heat; stir in chips and marshmallow crème till smooth.

Remove one cup from the mixture and set aside.

Add orange extract and food coloring to remaining mixture; stir until blended.

Pour the orange mixture into prepared pan.

Drop reserved marshmallow mixture by tablespoonfuls over the top; cut through with a knife to swirl.

Cover & refrigerate until set. Using foil, remove from pan and cut into squares.