Marbled Orange Fudge

Grease a 13x9-in. pan with 1-1/2 teaspoons butter; set aside., In a large heavy saucepan, combine the sugar, cream and remaining butter. Cook and stir over low heat until sugar is dissolved. Bring to a boil; cook and stir for 4 minutes. Remove from the heat; stir in chips and marshmallow creme until smooth., Remove 1 cup and set aside. Add orange extract and food coloring to the remaining mixture; stir until blended. Pour into prepared pan. Drop reserved marshmallow mixture by tablespoonfuls over the top; cut through with a knife to swirl. Cover and refrigerate until set. Cut into squares.