A cooked peanut butter fudge, very good and simple to make. In a saucepan, combine sugars, salt, and milk. Cook to 120ºC . Remove from heat and add marshmallows, peanut butter, and vanilla. Beat with a wooden spoon several minutes until thick and creamy and gloss disappears. Spread in a buttered 20 cm square pan. Cut into squares. Makes about 48 pieces.