2 cups granulated white sugar
½ cup milk
1 cup peanut butter (smooth or chunky)
1 teaspoon vanilla extract
Grease an 8-inch by 8-inch baking pan. In a medium saucepan, bring sugar and milk to a boil. Boil for about 2½ minutes, stirring regularly, then remove from heat. Add peanut butter and vanilla, and stir until smooth.
Pour the mixture into the pan and allow to cool until set. Slice into 1-inch squares.