A few minustes before you're done peeling, pause and preheat the oven to 250 degrees. Start layering the crayons in a muffin pan or mini-loaf pan as we used. Even better would be a shaped muffin pan. We did some crazy crayons, aka mixed up leftover crayons, and some in the same color range.
Heat in the oven for 7-8 minutes and begin checking the crayons every minute or so until they look like rainbow soup.