Marshmallow Swirl Fudge

Why I Love This Recipe
Found this on the web,sounds so good
Makes about 2 pounds fudge.
Ingredients You'll Need
3 - cups (1-1/2 packages) semi-sweet chocolate chips
4 - Tablespoons butter, divided
1 - can (14 ounces) sweetened condensed milk (not evaporated milk)
1-1/2 teaspoons vanilla extract
Dash salt
1/2 to 1 - cup chopped nuts
2 - cups miniature marshmallows
Directions
Line 8-or 9-inch square pan with foil.
In heavy saucepan over low heat, melt chocolate chips and 2 tablespoons butter with sweetened condensed milk, vanilla and salt.
Remove from heat and stir in nuts.
Spread evenly into prepared pan.
In medium saucepan over low heat, melt marshmallows with remaining 2 tablespoons butter.
Spoon onto fudge.
With table knife or metal spatula, swirl through fudge.
Refrigerate 2 hours or until firm.
Remove fudge from pan and peel off foil.
Cut into squares.
Store loosely covered at room temperature.