These were the crayons that I made for the lego party. I bought the silicone mold at lego.com and then collected up all the worn down and broken crayons in the house. I slit a line down each crayon with paper and then peeled the paper off. I broke all the crayons into small pieces and then put them in the mold to bake for about 15 minutes on 250.
TIPS: my first batch didn't go so well because I wasn't using enough crayon. You want to almost fill the mold so that you can push the crayon out from the backside. When you take them out of the oven, put them in the freezer for about 15 minutes and then you can get them out of the mold easier...without snapping their heads off. Also, the darker color crayons are OK if you only use one with lighter colors. If you use several darker colors together, they pretty much melt together and look black when they are re-hardened into new crayons.