Line a 9x13 inch dish with foil and spray with non-stick spray.

Combine chocolate chips, sweetened condensed milk, and butter in a medium saucepan. Melt over medium heat, stirring constantly until smooth.

Remove from heat and stir in vanilla extract, peanuts, and vanilla.

Place marshmallows in a large bowl.

Pour the melted chocolate mixture over the marshmallows and mix well. Let sit a few minutes if you want some marshmallows to remain unmelted.

Spread the mixture into the prepared pan.

Sprinkle with additional peanuts and marshmallows on top.

Refrigerate until firm, about 2-3 hours or overnight.