Peanut Butter and Soda Cracker Fudge

~When you eat this creamy confection, you'll never know crushed
crackers are inside.~

2 cups sugar
2/3 cup evaporated milk
30 saltine crackers (1 cup), finely crushed
1/3 cup creamy or chunky peanut butter
1/2 teaspoon vanilla
  Melted chocolate (optional)
  Chopped peanuts (optional)

Line a 9x5x3-inch loaf pan with foil, extending foil over edges
of pan. Butter foil; set aside.
  Butter side of a heavy medium saucepan. In the saucepan,
combine sugar and evaporated milk. Cook and stir over
medium-high heat until mixture boils. Boil for 1 minute. Remove
from heat. Add crackers, peanut butter, and vanilla, stirring
until peanut butter is melted. Let stand, without stirring, for
50 minutes. Using a wooden spoon, beat vigorously until fudge
becomes very thick and just starts to lose its gloss (about 6
minutes).
Immediately spread fudge into prepared pan.
  If desired, drizzle with melted chocolate and sprinkle with
chopped peanuts.
  When fudge is firm, use foil to remove from pan. Cut fudge
into 1-inch squares. Store tightly covered.

Makes about 1-1/3 pounds (45 squares)