Line a 9-in. square pan with foil and grease the foil with 2 teaspoons butter; set aside. In a large heavy saucepan, combine the sugar, milk and remaining butter. Bring to a full rolling boil, stirring constantly. Boil for 4 minutes over medium heat, stirring to prevent scorching. Remove from the heat and set aside., Divide marshmallow creme between 2 heat-resistant bowls; add chocolate chips and 1/2 teaspoon vanilla to 1 bowl, and peanut butter and remaining vanilla to the other. Pour half of sugar mixture into each bowl., Stir chocolate mixture until smooth and pour into prepared pan; stir peanut butter mixture and carefully pour over chocolate layer. Refrigerate until firm. , Using foil, lift fudge out of pan. Discard foil; cut fudge into 1-1/4-in. squares.