Old-Fashioned Chocolate Fudge

Butter a jelly-roll pan or an 8 x 8 -inch pan. Chop the chocolate in small pieces. Put the chocolate, sugar, milk, and corn syrup in a 3-quart heavy pot. Stir the ingredients to blend the mixture well.

Turn the heat on low and stirring slowly, bring to a boil. Cover the pot and let boil (over the low heat) for 2 minutes. Uncover the pot, and using a pastry brush, brush down the sides of the pot with the brush that has been dipped in cold water. (This helps the fudge not to become granulated.)

Continue to boil slowly, without stirring over the low heat, until the syrup reaches the soft-ball stage (it will read 234 degrees F on a candy thermometer.) Remove from the heat, add the butter without stirring, and set the pot on a cooling surface or rack. Do not stir until the syrup is lukewarm (110 degrees F), then add the vanilla and stir until the mixture loses its glass and thickens. Pour into the buttered pan and using a table knife mark it into the squares. When firm, cut into pieces and store airtight in plastic bags if not serving shortly.

OPTIONAL: If you wish, add 1 cup chopped walnuts when you add the vanilla.