Cacahuates garapiñados (Sugar-crusted Peanuts)

Few things bring out the ingenuity of Mexicans more than trying to make a living. People find all sorts of ways to make money, some more inventive than others. In Mexico City, there is a whole industry of people selling candies at street corners, walking among stopped cars at traffic lights. There were children selling tiny 4-packs of Adams chicklets, or adults selling all sort of Mexican artisan candies: glorias, muéganos, obleas. Some candies were easier to find than others. I remember having to go to a specific corner on particular days if I wanted to get muéganos.
One of my favorite candies was sugar-crusted peanuts. They must have been pretty old, because they were always rock-hard, but I loved them, anyway. (After all, that is how I knew them.) It was several years later, in Canada, that I learned to cook them at home. Because they are made fresh, they are no longer rock-hard; and they are so addictive, that we're guaranteed not to have them lyring around for too long.
Ingredients
2 cups raw peanuts with papery skins on
1¼ cup water
1¼ cup sugar
½ tsp vanilla (Mexican, if possible)
few drops of red food coloring (optional)
the peel from 1 lemon, shredded (optional)
Add the sugar and water to a large, deep skillet (I use a 10" one), at medium heat, stirring until the sugar is copmletely dissolved.
Set the heat to high and wait for the syrup to bubble. Add the peanuts and vanilla (and the coloring, if used) and stir constantly. The water will evaporate and the sugar will crystalize.
Once the sugar has the consistency of fine sand, about 10 minutes, remove from heat and let the mixture cool.
Once the sugar has cooled and hardened, return the mixture to medium heat and allow the sugar to dissolve, once again mixing constantly. The sugar will turn darker as it is dissolving.
When the peanuts are all more or less uniform in color (about another 5 minutes), remove from heat and transfer to a large pan greased with butter. Spread the peanuts out so they are in a single layer. Allow them to cool completely.
Notes
It is necessary to get peanuts with skins; otherwise, the sugar will not stick to the peanut well. If you cannot get raw peanuts, you can used toasted peanuts with skin--just know the peanuts will be cooking for several minutes in high heat.
Keep in mind that you're working with sugar at very high temperatures. Do not try to "lick the spoon" or try the peanuts until they have cooled. (Besides, the hot peanuts are soft, and you're missing on the nice crunch of candies.)
The traditional way of making them is using red food coloring. I don't bother with the coloring, and I added the vanilla to make them more irresistible. I'm trying to find a way to color them with beet juice, the natural coloring in red velvet cake (for natural coloring), but I haven't found the right amount of acid to stop the coloring from turning from a rich red to a flat brown when heated.