Peanut Fudge

Combine milk, corn syrup, sugar and chocolate in a heavy 2-quart saucepan. Cook over medium heat, stirring constantly, until the sugar is dissolved. Continue cooking over medium heat until the candy reaches the soft ball stage (236 F) on the candy thermometer. Stir occasionally to prevent sticking. Remove from heat and add butter. Cool to 110 F without stirring, then add the vanilla. Beat until fudge begins to lose its shine. Stir in the peanuts and quickly pour into a greased 8-inch square baking pan. Cut into squares when candy is completely cooled. Makes 1 1/2 pounds.