First of all... never throw away broken crayons... collect them in a little jar till you have a bunch. Then wait for a rainy day when you need a little activity to entertain your kiddo.
Give your little squirt the fun task of pealing the paper off of the broken crayons. Then they can break the larger pieces into smaller pieces. Fun Fun!
Have that sweetie pie distribute the crayons into muffin tins. I suggest using mini-muffin tins, as the results of my first try using regular muffin tins were a bit large for my Beni's little fingers. Better yet... heart shaped tins!
Now bake them until they melt (for 10-15 minutes) at 250°F or 120°C. Let them cool down completely and pop them out.
Now let your kiddo draw away.
Easy-Peasy... and fun for your little one!!