You don’t need the luck of the Irish to make this easy Lucky Charms Rice Krispie treats microwave recipe. That’s right, it’s everything you love about the classic treat bars, but with the addition of some lucky marshmallows that make them perfect for St. Patrick’s Day!

Why You’ll Love This Recipe
Rice Krispie treats are so easy to make in the microwave, and keeps you from having to stand over the stove constantly. In fact, the cooking time is only a few minutes, so you can have everything assembled in less than 10 minutes total!
This recipe is easy enough for the kids to help with, making for a fun family activity that’s delicious too!

While the Lucky Charms are perfect for St Patty’s Day, you can also feel free to swap in other types of cereals for festive treats year round. These marshmallow cereal treats work well with a variety of different cereals so you can really use whatever you have on hand.
Ingredients You’ll Need

- 5 Cups Rice Krispies cereal
- 4 Cups Lucky Charms cereal
- 16 ounces mini marshmallows
- 4 Tbsp salted butter
- 1 Tbsp green sanding sugar (optional)
- 1 Tsp vanilla extract
Ingredient Tips and Substitutions
- You can use name brand or generic cereal, either is totally fine!
- If preferred, use all Rice Krispies and only the marshmallows from the Lucky Charms (making it more similar in texture to a traditional Rice Krispie treat). However, it’s hard to find the “only marshmallows” version and tedious to pick them out from the rest of the cereal
- Swap in 64 large marshmallows in place of the mini if needed (note that they may require slightly longer to fully melt as well). You can also use flavored marshmallows such as chocolate if preferred
- If you don’t have salted butter, add ½ tsp salt in to compensate
- The sanding sugar is optional, but adds a fun sparkle of green which is perfect for St Patrick’s Day! Feel free to top your treats with other fun festive decorations, such as sprinkles, edible glitter, or icing in coordinating colors based on your theme!
How to Make Lucky Charms Rice Krispie Treats in the Microwave
- Grease a 13×9 pan (you may also use foil or parchment)

- To a large mixing bowl, add the butter. Microwave on high for 30 seconds until it begins to soften and melt

- Add the vanilla extract and marshmallows to the bowl with the butter

- Microwave on high for 60 seconds and stir. Continue microwaving in 30-second bursts and stirring until the marshmallows are melted (mine took 1 ½ minutes in total in a 1000W microwave)

- Add both cereals and the sanding sugar to the marshmallow mixture, and stir to coat completely

- Spread the coated cereal into the greased pan and press it down to form an even layer. I recommend spraying your hands well with nonstick spray, or using a greased spatula or a piece of wax paper (it is sticky!)

- Top with any additional toppings if desired (optional)
- Cool to room temperature (about 2 hours) or pop in the refrigerator (45-60 minutes), then cut into squares and serve!

What to Serve For Dinner When Lucky Charms Rice Krispie Treats Are For Dessert!
- Corned beef
- Reubens
- Bangers and mash
- Shepherd’s pie
- Cottage pie
- Stout pie
- Fish pie
- Cabbage
- Colcannon
- Boxty
- Irish soda bread
- Beef stew
- Potato soup
- Green beer
- Irish coffee
Complete your meal with my easy recipes for Air Fryer Reuben Sandwiches, Air Fryer Irish Soda Bread, or a warm bowl of Air Fryer Leek and Potato Soup.
Recipe FAQs
Is There a Way to Soften Rice Krispie Treats?
The best way to soften Rice Krispie treats is to increase the ratio of marshmallows to cereal, which will give you a softer texture.
Alternatively, pop your treat in the microwave for 30 seconds before eating to warm the sugar and make it softer.
Is It OK to Use Old Marshmallows For Rice Krispie Treats?
No, it is not OK to use old marshmallows for Rice Krispie treats. They actually lose elasticity, so they won’t melt or set well.
Use your old marshmallows in s’mores instead, where the dish isn’t as dependent upon the binder.
What is the Best Way to Cut Rice Krispie Treats?
Use a large knife, cookie cutters, or a pizza cutter that have been sprayed with nonstick spray to cut your Rice Krispie treats.
This will give you a clean cut with relatively little difficulty. Make sure to use wax paper between treats if you’re stacking them to store.
Can I Make Rice Krispie Treats the Night Before?
Yes, you can make Rice Krispie treats the night before. Fresh Rice Krispie treats last 2-3 days when stored in a sealed container at room temperature.
This ensures they have ample time to cool before you eat them.
How Long to Wait Before Eating Rice Krispie Treats?
You should wait around 2 hours before eating Rice Krispie treats, allowing them time to cool and set.
If you’re in a hurry, they may be placed in the refrigerator to accelerate cooling. Rice Krispie treats set in the fridge in about 45-60 minutes. Do not, however, store them in the refrigerator long term, or they will dry out.
How Do You Clean Up After Rice Krispie Treats?
You clean up after Rice Krispie Treats with hot water. The hot water will dissolve residual sugars and make your pans and hands clean up easily.
You can use soap as well of course, but the grease cutting properties really won’t assist as well as just plain hot water.
Can You Put Rice Krispie Treats in the Freezer?
Yes, you can put leftover Rice Krispie treats in the freezer. Simply defrost before consuming, or pop in the microwave for about 30 seconds.
Individually wrapping them in wax paper and then adding to a Ziploc bag makes it easy to remove only portions as needed.
Recipe Pro Tips
- This recipe may be scaled up or down to make different size batches. Leftovers freeze well, though, so don’t worry about making extra
- Fresh Rice Krispie treats are best enjoyed within 2-3 days for freshness
- Store your Lucky Charms Rice Krispie treats on the counter at room temperature with a lid or other covering. Do not put them in the refrigerator beyond cooling right after cooking. Storing them there will make them dry out
- Cut marshmallow cereal treats with a greased knife or use cookie cutters in seasonal shapes (like shamrocks!) to desired size

More Easy Microwave Sweets to Try
- Quick Microwave Chocolate Sauce
- How to Make Tanghulu in the Microwave
- Easy Microwave Peppermint Bark
- Microwave Chocolate Covered Strawberries
- Delicious Microwave Lemon Cake
Final Thoughts
These adorable Lucky Charms Rice Krispie treats are so easy to make in your microwave. You’ll have everything put together and cooling in under 10 minutes, making for a dessert that’s easy enough for weeknights!
They’re the perfect dessert for celebrating St Patty’s Day, or feel free to change the ingredients up for an easy to make sweet treat anytime.
This recipe is even kid friendly for your kitchen helpers! Thankfully, there’s no luck of the Irish needed to pull off this fabulous Lucky Charms Rice Krispie treat microwave recipe!

Easy Lucky Charms Rice Krispie Treats Microwave Recipe
Equipment
- Microwave
- Large microwave safe bowl
- 13×9 pan
- Measuring cups and spoons
- Spoon or spatula for mixing
- Nonstick spray, parchment, or nonstick foil
Ingredients
- 5 Cups Rice Krispies cereal (or generic brand)
- 4 Cups Lucky Charms cereal (or generic brand)
- 16 Ounces mini marshmallows
- 4 Tbsp salted butter
- 1 Tbsp green sanding sugar (optional)
- 1 Tsp vanilla extract
Instructions
- Grease a 13×9 pan (you may also use foil or parchment)
- To a large mixing bowl, add the butter. Microwave on high for 30 seconds until it begins to soften and melt4 Tbsp salted butter
- Add the vanilla extract and marshmallows to the bowl with the butter16 Ounces mini marshmallows, 1 Tsp vanilla extract
- Microwave on high for 60 seconds and stir. Continue microwaving in 30-second bursts and stirring until the marshmallows are melted (mine took 1 ½ minutes in total in a 1000W microwave)
- Add both cereals and the sanding sugar to the marshmallow mixture, and stir to coat completely5 Cups Rice Krispies cereal, 4 Cups Lucky Charms cereal, 1 Tbsp green sanding sugar
- Spread the coated cereal into the greased pan and press it down to form an even layer. I recommend spraying your hands well with nonstick spray, or using a greased spatula or a piece of wax paper (it is sticky!)
- Top with any additional toppings if desired (optional)
- Cool to room temperature (about 2 hours) or set in the refrigerator (45-60 minutes), then pop out of the pan, cut into squares, and serve!
Notes
- If preferred, use all Rice Krispies and only the marshmallows from the Lucky Charms (making it more similar in texture to a traditional Rice Krispie treat). However, it’s hard to find the “only marshmallows” version and tedious to pick them out from the rest of the cereal
- Swap in 64 large marshmallows in place of the mini if needed (note that they may require slightly longer to fully melt as well). You can also use flavored marshmallows such as chocolate if preferred
- If you don’t have salted butter, add ½ tsp salt in to compensate
- The sanding sugar is optional, but adds a fun swirl of green which is perfect for St Patrick’s Day! Feel free to top your treats with other fun festive decorations, such as sprinkles, edible glitter, or icing in coordinating colors based on your theme!
- This recipe may be scaled up or down to make different size batches. Leftovers freeze well, though, so don’t worry about making extra
- Fresh Rice Krispie treats are best enjoyed within 2-3 days for freshness
- Store your Lucky Charms Rice Krispie treats on the counter at room temperature with a lid or other covering. Do not put them in the refrigerator beyond cooling right after cooking. Storing them there will make them dry out
- Cut marshmallow cereal treats with a greased knife or use cookie cutters in seasonal shapes (like shamrocks!) to desired size
- Exact nutritional values will vary based on brand of ingredients, any added toppings, and size of your cuts, so please consider this a guideline only
Nutrition

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