Lucky Charms Sheet Cake
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This Easy Lucky Charms Cereal Sheet Cake combines your favorite cereal with a sweet (green!), fluffy cake, and a decadent, cereal-inspired buttercream frosting for a dessert that is magically delicious!
Who doesn’t love a bowl of Lucky Charms in the morning?! They are such a delicious way to start your day!
Combine the classic sweet cereal with a cake and you have one heavenly St. Patrick’s Day dessert.
This beautiful green cake is colorful, sweet, and perfect for St. Patrick’s Day.
Top it with rainbow sprinkles and Lucky Charm marshmallows, and you have a colorful treat that your entire family will love!
This colorful cake is packed with Lucky Charms flavor thanks to a little trick we use in the recipe–cereal milk!
You know the sweet milk leftover when you finish a bowl of cereal? That’s the stuff!
I will share how to easily make cereal milk and use it to make your cake packed with authentic Lucky Charms flavor.
For more Lucky Charms dessert ideas try my Lucky Charms Treats and Lucky Charms Pudding Parfaits.
Why You’ll Love This Lucky Charms Cake
- It’s great for St. Patrick’s Day!
- It’s colorful and fun for the kiddos.
- It gives you an excuse to enjoy one of your favorite childhood treats (not that you needed an excuse!)
- It’s sweet, creamy, and delicious!
- It will be a hit with your entire family.
Ingredients
This section includes ingredient notes and substitution options. Get all measurements, ingredients, and instructions in the printable recipe card at the end of this post.
- Lucky Charms Cereal– The star of the recipe!
- Milk– Whole milk will give you the richest flavor but you can use 2% or 1% if desired.
- All-Purpose Flour
- Baking Powder– Gives the cake the perfet rise.
- Cornstarch– Works to make the cake incredibly tender and moist.
- Salt– If using salted butter you can omit the added salt.
- Butter & Oil– This recipe uses a combo of butter and oil to give the cake the perfect texture. Vegetable or canola oil will work for this recipe.
- Sugar– You will need both granulated sugar for the cake and confectioners sugar for the frosting.
- Eggs– Remove from you eggs from the fridge at the same time as your butter to bring them to room temperature as well.
- Vanilla Extract– I always recommend 100% pure vanilla extract for the best flavor.
- Green Food Coloring– Optional, but perfect for a St. Patrick’s Day cake. If making for another occasion feel free to leave it out or use another color.
- Sprinkles– Optional, but fun!
How To Make a Lucky Charms Cake
This section shows you how to make the recipe with step-by-step photos and instructions. For the full printable recipe, see the recipe card below.
PREPARE CEREAL MILK
- Remove the marshmallows from the cereal and save them for later.
- Spread the cereal on a baking sheet and bake for 15 minutes, stirring halfway through.
- Soak the cooled cereal in milk for 15 minutes.
- Strain the milk from the cereal. Ta-da! You have cereal milk!
MAKE THE CAKE
- Whisk to combine the flour, baking powder, cornstarch, and salt. Set aside.
- Beat the butter, oil, and sugar until light-colored and fluffy, about 2 minutes. Beat in the eggs, vanilla extract, and ¾ cup of your cereal milk.
- Add the dry ingredients to the wet ingredients, mixing until just incorporated.
- If desired, mix in some green food coloring.
- Spread the batter into the pan and bake as directed in the recipe card below.
FROST & DECORATE
- Combine the confectioners sugar, butter, cereal milk, and vanilla to make your buttercream frosting.
- Frost your fully-cooled cake and top with sprinkles and your reserved Lucky Charms marshmallows.
What to Serve/Pair with Your Lucky Charms Cereal Cake
If you are anything like my family, you love to have ice cream with your cake! I always keep a tub of vanilla on hand in the freezer, just in case.
Want to pair a “grown up” drink with your Lucky Charms Cake? My favorite is this Grasshopper cocktail. It’s tasty and is a fun, colorful addition!
For a drink that the whole family can enjoy, pair your cake with a yummy Shamrock Shake or glass of Shamrock Punch.
Sometimes, you just need a little snack while you’re waiting on your cake to bake and cool so that you can enjoy it. To have something to munch on, make this 2-Minute Sweet & Salty Snack Mix.
Storage
This cake can be stored at room temperature or in the fridge. Because the icing is a buttercream, it does not need to be refrigerated. However, I find it does keep for longer in the fridge. Plus, I like the way that it tastes cold.
When storing, be sure to completely cover the cake and make it air-tight so that it does not dry out.
I do not recommend freezing this cake. It just won’t be as tasty once it has been frozen and thawed.
Tips and Tricks
- Looking for a shortcut? You can get the same look (but not the same taste) by using a box of white cake mix rather than baking your cake from scratch. Simply follow the directions on the box, adding food coloring if desired.
- If frosting is too thin mix in additional confectioners sugar by the Tablespoonful, as needed.
- Not a fan of sheet cakes? Divide the batter into 2 square or round pans to create a layer cake. Be mindful that it will take less time to bake however, so keep an eye on them in the oven.
FAQs
Technically, yes. If you do this, you can omit the baking powder and the salt, but I’ve found that the texture of the cake tends to turn out better with all-purpose.
Sure. If you are okay with the taste of the store-brand cereal, go ahead and try it.
Yes, this is an important step. Toasting the cereal helps keep the cereal from falling apart and allows the cereal’s flavor to soak properly into the milk, which is what will give your cake the Lucky Charms taste that you want.
When making cereal milk some of the milk gets absorbed into the cereal so after straining you end up with less milk than you started with. To be safe we are starting with plenty of extra milk. Feel free to enjoy any left over cereal milk on its own 🙂
More Tasty St. Patrick’s Day Dessert Ideas
Lucky Charms Sheet Cake
Ingredients
Cereal Milk:
- 3 cups Lucky Charms
- 2 cups milk
Cake:
- ¾ cup cereal milk
- 1 ¼ cups all-purpose flour
- 1 ¼ teaspoon baking powder
- 1 Tablespoon cornstarch
- ¼ teaspoon salt
- ½ cup unsalted butter room temperature
- 2 Tablespoons vegetable oil
- ¾ cup granulated sugar
- 2 large eggs room temperature
- 2 teaspoons vanilla extract
- Green food coloring optional
Frosting:
- ½ cup unsalted butter softened
- 3-4 cups confectioners sugar
- 2 Tablespoons cereal milk
- 1 teaspoon vanilla extract
- Rainbow sprinkles
Instructions
Prepare Cereal Milk
- Preheat oven to 300ºF and line a baking sheet with parchment paper or a silicone baking mat.
- Remove the marshmallows from the Lucky Charms cereal and reserve them for later.
- Spread the Lucky Charms cereal (no marshmallows) onto the baking sheet and bake for 15 minutes, stirring halfway. Allow cereal to cool.
- Place the cooled cereal and milk in a large bowl and allow to soak for 15 minutes.
- Drain, saving the milk and discarding the cereal.
Make the Cake
- Preheat oven to 350ºF. Line a 9 x 13 baking pan with parchment paper and coat with non-stick spray. Set aside.
- In a medium bowl, whisk to combine the flour, baking powder, cornstarch, and salt. Set aside.
- In a large bowl, beat together the butter, oil, and sugar until light-colored and fluffy, about 2 minutes. Beat in the eggs, vanilla extract, and ¾ cup of the reserved cereal milk.
- With the mixer on low, add the dry ingredients and mix until just incorporated.
- Mix in the green food coloring, if desired.
- Pour the batter into the pan and bake for 28-32 minutes, or until an inserted toothpick comes out mostly clean.
- Allow the cake to cool completely before frosting.
Make Frosting & Decorate
- In a large bowl, beat together 3 cups of confectioners sugar, butter, cereal milk, and vanilla extract for 2 minutes or until smooth and well-combined. If frosting is too thin add additional confectioners sugar by the Tablespoonful, as needed.
- Spread the frosting over the cooled cake and top with sprinkles and your reserved Lucky Charms marshmallows.
Notes
- Cover and store at room temperature or in the fridge for up to three days.
- Not a fan of sheet cakes? Divide the batter into 2 square or round pans to create a layer cake. Be mindful that it will take less time to bake however, so keep an eye on them in the oven.
Nutrition
Did You Make This Recipe?
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How many cupcakes would this make?
I would guess around 24 cupcakes. They will also take much less time in the oven, I would start checking on them at about 12-14 mins. If you decide to give the recipe a go as cupcakes please let me know they come out 🙂