If your kids are fans of store-bought LCM bars, then they're going to love this Rice Bubble Marshmallow Slice. With just 3 ingredients and 5 minutes of prep time, it's a quick and fun no-bake recipe that's perfect for lunchboxes, after-school snacks, or kids' birthday parties. Just like my Healthy LCM Bars, Strawberry Pancakes and Coco Pop Bars, this is one of those treats that disappears faster than you can say "what's for afternoon tea?"
Love this recipe! Made it several times and always a crowd pleaser.
- Jem
Also known as homemade rice krispie treats or marshmallow slice, this recipe combines butter, marshmallows, and rice bubbles to create a sweet, chewy, crunchy bar that kids (and big kids!) adore. It's the Aussie answer to lunchbox-friendly snacks, and a great alternative to the pre-packaged versions you'll find in the supermarket.
The beauty of this recipe is how versatile it is - add colourful sprinkles for parties, cut into mini squares for lunchboxes, or top with melted chocolate for something a little extra. It's freezer-friendly, fuss-free, and guaranteed to bring back those nostalgic childhood vibes.
If you love easy no-bake recipes, you'll also want to try my Mars Bar Slice, Honey Joys, or Chocolate Crackles too!
Why You're Going To Love This Recipe
- Only 3 main ingredients - just butter, marshmallows, and rice bubbles.
- 5 minutes prep - the fridge does the hard work for you.
- Lunchbox snack friendly - they stay crunchy in school lunch boxes all day (one of my kids' favourites!)
- Thermomix or stovetop - whichever method suits you.
- Freezer-friendly - make ahead and freeze for up to 3 months.
Jump to:
Slice Ingredients
You only need three simple ingredients to make this no bake rice bubble slice. Here are a couple of notes to make sure you get the best result:
- Rice Bubbles (Rice Krispies) - use a fresh, unopened box for maximum crunch. Stale cereal will make your slice soft and chewy instead of light and crispy.
- Marshmallows - regular-sized marshmallows melt more evenly than jumbo marshmallows or mini marshmallows. White marshmallows will give you a classic look, while pink ones add a fun pastel colour.
Variations
- Gluten-Free Rice Bubble Slice - use a certified GF puffed rice cereal and check your marshmallows.
- Chocolate Drizzle - once set, drizzle with melted white, milk, or dark chocolate.
- Birthday Party Slice - top with rainbow sprinkles or mini M&Ms before the slice sets.
- Mini Puddings in Ramekins - press the mixture into greased ramekins and top with sprinkles or chocolate for individual serves.
- Halloween Rice Bubble Slice - stir in orange and black M&Ms, candy eyes or candy-coated chocolates, then drizzle with melted white chocolate tinted orange for a fun Halloween recipe.
Need To Substitute An Ingredient?
Ask ChatGPT for suggestions on how to substitute the particular ingredient:
How To Make Rice Bubble Marshmallow Slice
This slice couldn't be simpler - three steps and you're done!
Note: Scroll to the recipe card at the bottom for the ingredients quantities and full detailed method.
- Step 1: Melt: Place butter and marshmallows in a large microwave-safe bowl. Heat on 50% power, stirring every 30 seconds until smooth.
- Step 2: Mix: Add the cups of Rice Bubbles and stir until completely coated.
- Step 3: Chill: Press firmly into a lined baking tray or cake tin, scatter with sprinkles, and refrigerate for at least 2 hours before slicing.
Top Tip
Use a piece of baking paper to press the mixture down firmly and evenly into the tin - it stops the mixture sticking to your spoon or hands and helps the slice hold together when cut.
Recipe Tips
- Always use a new, unopened box of Rice Bubbles for maximum crunch.
- Work quickly when mixing the marshmallow mixture through the cereal - it sets fast.
- To stop sticking, grease your spatula or hands lightly with butter before pressing into the tin.
- Slice the bars while still slightly soft (after chilling for 1-2 hours), for neat, clean edges.
- Store in an airtight container in the fridge for up to 1 week.
- Freeze in individual portions in ziplock bags for up to 3 months. Defrost in the fridge overnight or pop straight into lunchboxes to thaw by recess.
- For parties, cut into mini squares so you get more servings out of one batch.
Rice Bubble Marshmallow Slice FAQs
Yes! Just swap in a certified gluten-free puffed rice cereal and check the marshmallows are gluten-free too.
Always store in an airtight container. Using fresh Rice Bubbles makes the biggest difference.
It's normal for it to be sticky when warm. Press it into the tin using baking paper or a greased spatula for best results.
Chill until set but not rock hard. Use a sharp, serrated knife and cut in one clean motion.
More Recipes Using Rice Bubbles
Rice bubbles (or rice krispies) not only make a simple and tasty breakfast, but they can also be used in SO many yummy baking recipes.
Here are a few of my most popular recipes using Rice Bubbles:
Rice Bubble Marshmallow Slice
Ingredients
- 200 g marshmallows see notes
- 75 g butter
- 165 g (5 cups) rice bubbles or any puffed rice
- 100s and 1000s/sprinkles to decorate, optional
Instructions
- Line the base and sides of an 18cm x 28cm (7 x 11 inches) rectangular slice with baking paper and set aside.
- Place the marshmallows and butter into a large microwave safe bowl. Melt in the microwave on 50% power for 2 minutes (or until just melted), stirring every 30 seconds. If using a Thermomix: Cook the marshmallows and butter for 4 minutes, 80 degrees, Speed 1 (scrape down the sides of the bowl after 2 minutes).
- Add the rice bubbles to the marshmallow mixture and stir until all of the rice bubbles have been coated in the marshmallows.If using a Thermomix: Add the rice bubbles to the bowl and mix for 1 minute 30 seconds, Speed 1, Reverse (using the spatula to help mix).
- Press the mixture into the prepared tin and sprinkle with 100s and 1000s.
- Chill in the fridge for a minimum of 2 hours.
Notes
- Always use a new, unopened box of Rice Bubbles for maximum crunch.
- Work quickly when mixing the marshmallow mixture through the cereal - it sets fast.
- To stop sticking, grease your spatula or hands lightly with butter before pressing into the tin.
- Use a piece of baking paper to press the mixture down firmly and evenly into the tin - it stops the mixture sticking to your spoon or hands and helps the slice hold together when cut.
- Slice the bars while still slightly soft (after chilling for 1-2 hours), for neat, clean edges.
- Store in an airtight container in the fridge for up to 1 week.
- Freeze in individual portions in ziplock bags for up to 3 months. Defrost in the fridge overnight or pop straight into lunchboxes to thaw by recess.
- For parties, cut into mini squares so you get more servings out of one batch
Wilson Deborah says
Absolutely love it
Jem says
Love this recipe! Made it several times and always a crowd pleaser.
Lucy says
Thank you so much!
Niah says
Opps found it thanks
Niah says
You never said how much butter you need to put into the slice
Niah says
Never mind i found it