I made these years ago with my two oldest kids when they were much younger. I saw it on Pinterest recently and thought I'd do them again with my two younger kids.
Since I still had the silicone heart mold and a box of broken, old crayons... and recent County-wide ruling at the schools to no longer allow candy with Valentines, it only made sense to do this. Considering I had everything at home already, 48 valentines cost $0!
First you need to peel and break many crayons. We had a bunch of used, no-point and sometimes-broken crayons in a big container so we used those. This took For-ev-er to peel! I eventually learned that if I took a paring knife and shaved the paper in a long strip down the side, I could peel the paper much faster. I did not allow the kids to attempt this part as I was pretty certain someone would cut off a finger.
They had to use fingernails and lots of patience. Mommy used the paring knife.
Then you need to break the crayons into small pieces. Each crayon essentially was broken into four pieces. I didn't chop mine to avoid messing up my good knives... they snapped just fine. Granted, it made for bigger pieces, but I think the result was fine.
Grab a small handful to put in the bottom of the silicone tray. The amount I used above still showed some of the red bottom, but it gave me a 1/4"- 1/2" thick crayon in the end which was good. (They pop out easily... no need to use anything on the tray first).
Bake at 230 degrees for 15-17 minutes. As you can see, sometimes the top crayons weren't perfectly melted at 15 minutes, so I tried to go a little longer.
To let them solidify quickly, I put them in the fridge to set.
After they were solid, I popped them out... just push on the bottom.
Unfortunately with a six-cup muffin tin, the process was long. Each "batch" took about 30-45 minutes since I had to wait till they were set to begin a new batch. My 48 crayons took about 5 hours total (I did other things while waiting, of course!) If you plan to do this more than one time, I'd definitely invest in a 12-cup pan or more.
I made little circles for the hearts to attach to. Now the problem was... how to attach them!!?
I tried hot glue. My thought: Put a huge glob on there and help the glue mix with the slightly-melted wax to make it stay better. The result: The crayon would appear to stick well for about 10 minutes, and then it would pop off.
Tape didn't stick to wax.
I'm sure you could simply put these into little plastic candy bags and attach a card... which is what I did years ago. However, I didn't have any at home and needed to figure this out.
So, I used a stapler. From behind, I stapled the circle into the wax heart... one staple. I realize it's not an ideal situation, but we're handing these to first and second graders, not preschoolers. The staples stuck in REALLY well. The crayons were not popping off at all. So, it'll take a deliberate pull to get it off (not too hard though... it is only wax)... and I figure at that point the circle card will be trashed. Hopefully the kids will wait till they are home to do this so that their parents can see this awesome little craft. Ha ha :) I tried to think of all possible harms that could come about from staples, but the truth is that our kids are exposed to staples ALL THE TIME from two-pocket folders to packets sent home to all sorts of paperwork and books... and my kids almost never get injured (ahem... unless they try to use a stapler on their own at home without asking while keeping a finger in the way... don't ask).
One crayon broke on me, so I used it to show how cool the crayon is. The above was made simply by rotating the crayon a little as I went along. Lots of fun colors!
I'm sure you can use all sorts of shapes and tins... but the obvious choice for Valentine cards was hearts. :)