Found this on the net at CopyKat recipes. I don't know if it's like See's, because I've never had See's. But I do know it's good!
- Put butter, chocolate and vanilla in medium bowl.
- In med saucepan, mix sugar, milk and marshmallows.
- Bring to a boil over med heat, stirring.
- Reduce heat to low and cook for 6 minutes, stirring constantly.
- Pour hot mixture over chocolate in bowl.
- Beat with mixer until thick and dull, (this doesn't take long).
- Stir in nuts.
- Pour into buttered 8x8 pan.
- Refrigerate until firm.