I grew up eating these and still make them with a slight variation... I use shredded wheat instead. Sometimes I mix shredded wheat and coconut. I also make a white chocolate version (with a green tint). Usually only around easter. You actually can make these to be less kid like, reducing the sugar and upping the presentation at bit.
Here's how I do it:
Ingrediants:7 oz milk chocolate
1 oz bittersweet chocolate
2 T butter
4 to 5 oz crumbled shredded wheat. You can substitute coconut or mix these two ingredients.
Method: Melt the chocolates and butter together then stir in the cereal.
Drop onto wax paper or into cups and make small indentation in center. Fill with easter eggs or Jordan almonds and cool.
I also dug though my old family recipe box and found this which is a more proper Crackle IMHO:
Ingredients½ C butter, cubed
1 tbsp cocoa powder
2 oz milk chocolate
1/3 C corn syrup
4 or 5 Shredded Wheat (full size) crumbled
Method - Put the butter into a medium bowl, then add the cocoa powder, chocolate and syrup. Microwave on high for 1 minute 30 seconds, or until melted, then stir to mix everything together. Mix in Shredded Wheat. Make into nests or wreaths and decorate while still warm. Cool.