It's a very simple concept. Hershey Kisses are unwrapped and set upon waffle pretzels. The Kisses and pretzels go into a cool oven of 250 degrees for five to eight minutes. Once the chocolate has just started to glisten and lose a bit of its form, it's time for the M&Ms. This job has always been reserved for mom. M&Ms are pressed into each softened Kiss. The chocolate takes at least a couple hours to harden again. This is important for packing them up and gifting.
When I first read about making them, the tutorials cautioned against using Kisses other than milk and dark chocolate. I wasn't convinced this was necessary. We have tried a variety of Kisses including caramel, mint truffle, Hugs and white chocolate with candy canes. What I will note is that each variety seems to melt at varying lengths of time and the caramel sometimes makes a big mess if they get too soft. However, those ones are especially tasty. The specialty Kisses seem to take the least amount of time, then milk chocolate, and finally the dark chocolate takes the longest. The softness can be checked with the back of a spoon. Another thing I always do now is to only bake one variety at a time.