Hard Rock Candy

Roll the edges of two 16 inch square pieces of heavy duty aluminum foil. Sprinkle the foil very generously with confectioners' sugar.
In a large heavy saucepan, combine the white sugar, corn syrup, and water. Heat over medium-high heat, stirring constantly until sugar dissolves. Stop stirring, and boil until a candy thermometer reads 300 to 310 degrees F (149 to 154 degrees C). Remove from heat.
Stir in the cinnamon oil and food coloring. Pour onto the prepared foil, and allow to cool and harden. Crack into pieces, and store in an airtight container.