Peanut Butter Fudge

1 1/2 C. firmly packed light brown sugar
1 C. sugar
1/2 C. butter
5 oz. evaporated milk
2 C. crunchy peanut butter
7 oz. marshmallow cream
1 tsp. vanilla

Line a 9 inch square baking dish with aluminum foil and grease lightly with butter.
In a large saucepan, combine brown sugar, sugar, butter, and evaporated milk. Cook over medium heat, stirring frequently, to 238 degrees on candy thermometer (soft ball stage).
Remove from heat and stir in peanut butter, marshmallow cream, and vanilla until combined. Pour into prepared dish and let cool completely. Cut into 1 1/2 inch squares.