Cover countertop or work surface with a silicone baking mat.

In a heavy-bottomed metal saucepan or stock pot, stir together granulated sugar, corn syrup, and water. (See notes on pan sizes, below.)

Cook over medium heat, stirring occasionally until sugar dissolves, then stop stirring

Cook, without stirring, until syrup reaches 300° F / 149° C on a candy thermometer, about 15 minutes. To prevent crystallization, periodically swirl the pan to keep the mixture moving, and frequently brush down sides of pan with a wet pastry brush.

Remove from heat. Stir in flavoring and gel food coloring.

Pour out onto prepared baking mat.

Cool completely, about15-20 minutes.

With your hands or a kitchen mallet, break the slab into small pieces.

With gloved hands, toss candy pieces in confectioner’s sugar.

Store old-fashioned hard candy in an airtight container at room temperature for up to three months.