Line an 8″ square baking tray with non-stick paper. Put the butter and marshmallows in a pan (big enough for you to get all those Rice Krispies in later!)
Put the butter in the bottom of the pan, not on top of the marshmallows like I’ve done here – it will stop the marshmallows from getting scorched and burnt. Heat the pan over a gently heat, stirring it regularly. As the marshmallows melt it starts to look like marshmallow soup.
Keep going until they’ve all melted and the butter is well worked in. Now off the heat and in goes the Rice Krispies.
Stir it up, making sure they’re all evenly coated.
Tip it into the tin – it’s sticky watch out!
Don’t try and spread it in the tin right away you’ll end up in a right sticky old mess, give it a minute or two to start to cool down. Spread it out using the back of a fork. If the marshmallow coating is still stringy and sticking to the fork let it cool a little more. Once you can do it without it sticking, spread it and level it out with the fork.
That’s it, leave it to one side to cool fully, decorate with whatever you fancy and set then eat away! Great for moulding and using for cake decorating too.