Place marshmallows in freezer for 10 minutes prior to making the fudge.

Line 9x9 inch pan with foil and grease with 1 tablespoon butter.

In a medium saucepan heat butter and sweetened condensed milk.

Add chocolate and stir until melted.

Remove from heat then add vanilla, stir well.

Fold in cold marshmallows and peanuts. Pour into pan and refrigerate for 3-4 hours.