Marshmallow Marble Top Fudge
["3 c. semi-sweet chocolate chips", "4 Tbsp. butter, divided", "1 (14 oz.) can sweetened condensed milk", "1 1/2 tsp. vanilla", "dash of salt", "1/2 to 1 c. nuts", "2 c. miniature marshmallows"]
["Line 8 or 9-inch square pan with foil; set aside.", "In heavy saucepan over low heat, melt chocolate chips and 2 tablespoons butter with sweetened condensed milk, vanilla and salt.", "Remove from heat.", "Stir in nuts.", "Spread evenly into prepared pan."]
["semi-sweet chocolate chips", "butter", "condensed milk", "vanilla", "salt", "nuts", "marshmallows"]