1
Butter a slice pan and line with baking paper. Melt butter in a large saucepan over gentle heat.
2
Add marshmallows and cook, stirring constantly, until marshmallows have melted.
3
Add rice bubbles and stir quickly to combine.
4
Tip bubble mixture into prepared tin and press down using the back of a clean spoon. Once cool, cut into slices or bars.