this is how i make my rice crispy treats.
The problem is that i cann't give you exact measurements because i never measyure when i do it.
melt in the pot low heat approx 100g of butter. ( unsalted)
add 5 or six big marsbars ( cut them into small pieces)
with a whisk or wooden spoon stir constantly til it is all melted and is stirred together. it is all smooth creamy looking. turn the cooker off. Now add rice crispies. and mix all together add a little at the time til you see that crispies are all covered and not too much mars melt left. don't add too much crispies but not too little either.
let it sit for few minutes. because it will be too hot for your hands to work with it but don't let it cool down because you cann't shape them if they are cold.
You can shape anything out of them and to get a smooth outside you could cover it with ganache if you want to.
i made my boys birthday cake using this for the towers
but most of the time people order them as little balls ( like cakeballs you make) they taste great like toffee crisps. nobody will think that you used mars bars to do it
i have aslo made them like cookies on the stick.