Butter and marshmallows melted in the microwave, poured over rice bubbles, pressed into a tin. That’s the whole recipe, and it takes about 10 minutes of actual work.
It makes 24 squares out of three ingredients, which is why it turns up at every school fete and every kid’s party. Chuck a packet of Skittles or mini M&M’s through it and it goes from plain to the thing they fight over.
No oven, no baking, and nothing that needs any skill. This is the one to hand to a kid who wants to make something.
Why You’ll Love It
Three ingredients and one of them is butter. It costs almost nothing and it makes 24 squares, so it’s one of the cheapest things you can send to a fete or a party. There’s no oven involved, which matters in summer. And it’s genuinely a recipe a kid can do most of themselves, with an adult on microwave duty.
Handy Tips
Watch the microwave rather than walking away, because marshmallow puffs up fast and will climb out of the bowl if you give it the chance. Use a big enough bowl for that reason, bigger than you think you need. Mix the melted marshmallow through the rice bubbles quickly while it’s still hot and loose, since it stiffens as it cools and gets hard to work with. Press it down firmly with a second sheet of baking paper over the top, which stops it sticking to your hands and gives you a compact slice that holds together when you cut it. Loose pressing is why slices crumble.
Make It Your Way
This takes colour and add-ins well, so it’s easy to make it fit an occasion. Lollies stirred through the mix give you flecks all the way down; scattered over the top before it sets and pressed in lightly, they stay bright and visible. Melted chocolate spread over the top once it’s chilled turns it into more of a proper slice, though you’ll want to score the squares before the chocolate sets hard or it will shatter when you cut it.
How to Store It
Keep it in an airtight container at room temperature rather than the fridge, where it holds for up to 3 days. The fridge makes it hard and a bit chalky, which is the opposite of what you want. Put a sheet of baking paper between layers if you’re stacking the squares, since they’ll stick to each other. If it’s a hot day the container is better off somewhere cool, because the marshmallow softens and the squares start to slump.
Other Recipes You’ll Love
Rice Bubble Slice
Prep Time 10 minutes 
Chill Time 3 hours 
Total Time 3 hours 10 minutes 
Ingredients
Equipment
Method
- Melt butter and marshmallows in the microwave for about 1.5 minutes (keep an eye on it so it doesn’t overflow).
- Mix until smooth, then pour over rice bubbles.
- Add skittles or m&ms if you like, and mix thoroughly.
- Pour into a lined slice tin, cover with baking paper and press down so it’s nice and compact.
- Chill, cut into squares, and eat!
Nutrition
Video
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FAQs
Can I use a different cereal?
Cornflakes work, though they break up more and the slice is less even. Anything light and crisp will hold together in the marshmallow; anything heavy sinks.
Why did my slice go hard?
Usually the marshmallow was overheated. It only needs about 90 seconds, and once it goes past melted it starts to turn to toffee, which sets rock hard as it cools.
Can I use marshmallow fluff instead of marshmallows?
It works but it’s sweeter and softer, and the slice doesn’t hold its shape as well when you cut it. Whole marshmallows are the more reliable option.
How long does it need to chill before cutting?
Long enough to set firm all the way through. Give it at least an hour in a cool spot, and don’t try to cut it while the middle is still soft or the squares will fall apart.
