One of the best I have found is one that involves square pretzels and Hershey's Hugs. It's the perfect combo of sweet and salty and my co-worker proclaimed them "crack." It's easy for my three year old to follow the directions on but I had to watch him as he'd eat a pretzel, then eat a hug and then put them on the cookie sheet. This involved a lot of handwashing as you could imaging.
Sweet and Salty Pretzel Hugs
found on Pinterest
bag of square pretzels
bag of Hershey's Hugs
Preheat oven to 300 degrees. Line parchment paper on cookie then place pretzels on the sheet. Then top with Hugs. Bake for 2.5 mins until the chocolate is glossy. Remove from oven and press down melted Hugs with a square pretzel.