Line a 8x8 baking pan with foil and spray with non-stick spray.
In a large bowl add chocolate chips, condensed milk and butter. Heat on high in the microwave for 1 minutes, mix. If chocolate chips are not fully melted, microwave an additional 10-15 seconds until morsels are melted. Stir in vanilla, marshmallows and 1 cup of the nuts.
Spread fudge into the 8x8 baking pan, top with the rest of the nuts and gently press. Chill for 4 hours. Slice into 1 1/2 inch squares.
**To keep the miniature marshmallows from melting, you must freeze them for a couple hours prior to adding them to the fudge mixture.
Notes
Store in an airtight container at room temp for 2-3 weeks