The fudge craze of the 1890s sent American cooks searching for exotic versions, and panache made its way into mainstream American cooking in that period.
Boil the milk with the brown sugar until it candies; just before it is done, add the butter and vanilla extract. Add the walnuts just before taking the candy from the fire. Stir the nuts in thoroughly, and pour the mixture into buttered tins. With a sharp knife divide at once into squares.
