2 cups sugar
1/2 cup milk
1/2 cup half-and-half
1 tablespoon light corn syrup
1 tablespoon butter
1 teaspoon vanilla extract

Line 8x4 inch loaf pan with foil, extending foil over edges of pan. Butter foil. Butter inside of heavy saucepan. Combine sugar, milk, half-and-half and corn syrup. Cook and stir over medium-high heat till mixture boils. Clip candy thermometer to pan side. Reduce heat to medium-low. Continue boiling at moderate, steady rate, stirring often, about 25-35 minutes till mixture reaches 238°F, soft ball stage. Remove pan from heat. Add butter and vanilla but do not stir. Cook without stirring for about 30 minutes to 170°F. Remove thermometer. Beat mixture vigorously with wooden spoon till fudge becomes thick and starts to lose its gloss, about 5 minutes. Immediately spread fudge into prepared pan. Score into squares while still warm. When firm, use foil to lift fudge out of pan and cut into squares.
Soft Ball Stage
Drop small amount of hot candy mixture into cold water. When removed from water, ball of candy should instantly flatten and run over your fingers.