Pour the hot water into the bowl of an electric mixer fitted with the paddle attachment. Stir in the gelatin, corn syrup and salt. Mix on low until the gelatin is dissolved. Turn the mixer on low speed and beat in the confectioners’ sugar 1 cup at a time.
Transfer the dough to a work surface dusted with confectioners’ sugar. Knead in more confectioners’ sugar until the dough is smooth and pliable.
Divide the dough into 6 pieces. Flatten one piece into a disk and cover the rest with plastic wrap. Add a few drops of pink food color and mint extract to the center of the dough and fold in the sides. Knead until the color and flavor is distributed. If dough becomes tacky with these additions, knead in more confectioners’ sugar. The drier the dough, the firmer the end result will be – and that’s what we want!
Repeat the coloring and flavoring process as follows: Tint a portion yellow and add lemon flavor, tint a portion green and add lime flavor, tint a portion orange and add orange flavor tint a portion purple and add clove flavor. Leave one portion untinted and add cinnamon flavor.
Sprinkle a work surface liberally with powdered sugar. Roll out one of the colored doughs on the work surface; lift it every so often to make sure it isn’t sticking. If the dough sticks add more powdered sugar underneath. Cut out the wafers using a 1.5-inch round cutter. Transfer the rounds to a large baking pan dusted with powdered sugar. Repeat with remaining dough.
Let the wafers stand at room temperature, uncovered for 24 hours. Flip the wafers and allow them to dry for another 24 hours. When the wafers are set, they should be firm and have a snap when you bite them. If you have trouble getting the wafers to dry crisp, dredge them in cornstarch and let them stand an additional 24 hours.
Roll set wafers in waxed paper and fold ends; secure with cellophane tape. You may also store them at room temperature in an air-tight container. Candies will keep for months.