Butter sides of a 3-quart heavy saucepan or Dutch oven. Combine sugar, corn syrup, and water in pan. Stirring constantly, cool over medium-low heat until the sugar is dissolved. Using a pastry brush dipped in hot water, wash down any sugar crystal on sides of pan. Increase heat and bring to a boil. Do not stir. Continue to cook until the syrup reaches the hard crack stage (300 to 310 degrees) and turns a light golden color.

Remove from heat and add butter and salt; stir until butter melts. Add baking soda ; stir until soda is dissolved. Stir in candy corn. Pour onto a large piece of heavy duty foil and using 2 greased spoons, pull edges of warm candy until stretched thin. Cool completely. Break into pieces and store in an airtight container.