Add the sugar to a large pot fitted with a candy thermometer. Sift in the cornstarch and whisk into the sugar until well-combined. Add the butter, corn syrup, salt, water, vanilla, and flavor extract of choice to the pot. Whisk to combine, then turn the heat to medium and cook until the mixture reaches 250°F (120°C).
2. Step
Add the food coloring and stir to combine.
3. Step
Pour the candy into a greased heatproof dish and cool until you are able to handle it, 5-10 minutes.
4. Step
Stretch the mixture out 12 inches (30 cm) (or further) and fold it over itself again and again for 10-15 minutes. The taffy will turn from translucent to opaque.
5. Step
When the taffy becomes harder to pull, roll it to about a 30-inch (76-cm) long and 1-inch (2-cm) thick log on a greased surface. Cut the log in half. Then slice the taffy into bite-size chunks.
6. Step
Wrap each piece of taffy in a square of parchment paper and twist the ends to seal.
