Liquid food coloring5-15 drops, depending on desired intensity
Line an 8x8x2 inch pan with foil. Use oil or cooking spray to grease it. (If using candy molds, set them on a baking sheet for support and lightly coat them with butter or cooking spray.)
Combine the sugar, corn syrup, and water in a medium saucepan over high heat. Bring to boil, stirring occasionally.
Clip a candy thermometer onto the edge of the pan, taking care the bulb doesn't touch the bottom of the pan. Continue to boil, stirring occasionally, until the mixture reaches 300°F/150°C (hard crack stage). To make sure it's reached the proper stage, drop a tiny amount in a cup full of ice water then fish it out with a spoon. Take a bite -- if it crunches, it's ready. If not, wait a minute then try again.
Working quickly, remove the pan from the heat. Take out the thermometer and stir in the coloring and flavoring. Pour the candy into the foil-lined pan or sprayed molds.
If using a foil-lined pan, score the candy into 1/2-inch squares using a pizza cutter or butter knife. If the lines don't hold shape, wait 2 minutes then try again.
Wait 20 minutes then separate the candy into squares, or pop it out of the candy molds. Enjoy!