Weekend Cooking: Potato Caramel

Boil together one cupful of granulated sugar, one cupful of coffee A sugar, one-half cupful of Irish potato—treated as before—one tablespoonful of butter, one cupful of milk, caramel coloring. Stir continually until the mass forms a soft ball in cold water. Then pour it onto a well oiled marble between candy bars.

From: Candy-Making Revolutionized: Confectionery from Vegetables by Mary Elizabeth Hall (1912 US)