Instructions

1. Place1 cup powdered sugar and 2 1/2 tablespoons nonfat powdered milk in a sifter or fine-mesh strainer and sift into a large bowl. Add 1/8 teaspoon kosher salt.
2. Line a baking sheet with a silicone baking mat and set it near the stove. Place1/2 cup granulated sugar, 1/3 cup corn syrup, and 2 tablespoons unsalted butter in a 2-quart or larger saucepan. Cook over medium heat until the sugar dissolves and the butter is melted, swirling the pan gently once or twice, 6 to 8 minutes.
3. Clip a candy thermometer or instant-read thermometer to the side of the pan. Bring the syrup to a full boil. Continue boiling without stirring until the syrup is 245°F to 250°F, 1 to 5 minutes. If you go over the temperature, remove the pan from the heat and quickly add a few tablespoons of water to the pan to reduce the temperature, and monitor the temperature carefully as it reheats. Remove from the heat immediately once the syrup reaches temperature.
4. Add 1 1/2 teaspoons vanilla extract. Be very careful since the syrup will bubble up and sputter quite a bit when you add the vanilla.
5. Add the powdered sugar mixture and stir with a stiff heatproof spatula until you've formed a thick paste-like dough and very little dry mixture remains. (I've found that it smells quite bad at this point — have faith!)
6. Pour all the dough onto the baking sheet, scraping the pan as well as you can.
7. Let the dough cool until you are able to handle it, 10 to 15 minutes. Don't wait too long, though; the dough will stiffen as it cools and become harder to roll out.
8. Cut the dough into 3 pieces using a bench scraper or chef's knife. Make a well in the center of one piece and add 10 drops of yellow food coloring. Make a well in the center of a second piece of dough and add 10 drops of yellow food coloring and 5 drops of red food coloring (to make orange).
9. Knead both pieces of dough until uniform in color. Be sure to leave the remaining white piece of dough well away from the kneading area so it doesn't get any color. Knead against the baking mat so you don't dye your countertop or work surface. You can also knead more dye into the dough if the color doesn't seem quite right to you.
10. Pinch off a piece of dough from each color roughly the size of a ping-pong ball. Roll each one into a thin 1/4-inch-thick rope. If a rope gets too long and hard to roll, you can break off the end and smash it back into the remaining dough.
11. Arrange the ropes side by side in whatever order you like (yellow-orange-white is classic!), and then gently pinch them together so they stick to each other.
12. Gently roll over the ropes with a rolling pin just to flatten out the curved edges.
13. Use the bench scraper or chef's knife to cut out triangles of candy. Angle your scraper at a forward-slash angle and then at a back-slash angle as you work down the length of the ropes.
14. Continue rolling and cutting the dough until it's all used up. If the dough becomes too stiff to work with, microwave individual pieces in 5-second increments until it becomes pliable again.
15. Spread the candies out onto the baking sheet in a single layer to dry for a few hours. Separate any candies that are sticking together. Once dry, the candies can be stored in an airtight container for several weeks. Like commercial candy corn, these candies are good until they become too dry to chew!