1 16-ounce package light brown sugar
1 5-ounce can evaporated milk
4 tablespoons butter or margarine (1/2 stick)
1 teaspoon cider vinegar

1 teaspoon vanilla extract
1 12-ounce jar chunky peanut butter

Butter 8 X 8 baking pan; set aside

In heavy 3-quart saucepan, mix brown sugar, undiluted evaporated milk, butter or margarine, and vinegar.
Heat to boiling over medium-low heat stirring constantly.
Set candy thermometer in place and continue cooking, without stirring.
Cook to 238 degrees, or soft-ball stage.
Remove saucepan from heat.

With wooden spoon, beat until mixture begins to thicken and cool slightly.
Stir in vanilla extract and peanut butter until well blended.
Pour into pan. Refrigerate until firm.
When cold, but into 6 strips, then cut each strip crosswise into 6 pieces.

Store fudge in tightly covered container.

Makes: about 2 pounds fudge or 36 pieces.