Hearts, stars, horseshoes, clovers, and blue moons decorate this fun lucky charms cake!
Get the luck of the Irish with this festive St Patrick’s Day cake that is decorated with lucky charms marshmallows. With delightfully moist green ombre layers inside, this stunning lucky charms cake boasts a hint of coffee and Irish Cream.
This lucky charms cake has been over a year in the making. If you follow me on Instagram, you may remember my that I posted some stories about lucky charms marshmallows last year. After spending hours separating the marshmallows, I discovered that each box contains an equal number of each shape.
While not super useful information, be confident in your need for just one family sized box of lucky charms cereal. It provides more than enough marshmallows.
Can You Buy Just The Lucky Charms Marshmallows For This Lucky Charms Cake?
In 2017, General Mills ran a promotion for 10,000 boxes of marshmallow only lucky charms. They could only be won with codes from specially marked boxes. However the promotion for these coveted boxes has ended and the marshmallow only boxes are no longer available. Instead, you have to sort out the magically delicious lucky charms marshmallows from a standard box.
If you aren’t beholden to the original lucky charms marshmallows, you can buy “Charms Cereal Marshmallows” on Amazon. They resemble the originals enough to still give the same visual appeal of this cake. Only upon closer inspection will people realize that the marshmallows are missing decorative features like the green clovers and orange stars.
Tips For Making a Perfect St. Patrick’s Day Cake with Lucky Charms Marshmallows
Baking is a science, and the foundations can make or break your cake’s quality. Here are some great articles to help you master this St. Patrick’s Day cake.
- The Creaming Method. This is the baking method used to incorporate the ingredients into the cake batter. The correct order determines whether or not the cake is fluffy and moist, or dense and dry.
- What Eggs Do In Baking. It’s amazing how much a simple ingredient impacts a recipe. Read this to find out exactly why it is important to add your eggs one at a time.
- Different Kinds Of Flour. This recipe can be made with all-purpose flour, but cake flour makes this St. Patrick’s Day cake more divine. Find out why.
How Long Does It Take To Make This Lucky Charms Cake?
What really makes this St. Patrick’s Day cake stand out is the pattern of the lucky charms marshmallows. In fact, the marshmallows even follow the pattern of the jingle: heart, stars, horseshoe, clover, blue moon, unicorns, rainbows, red balloons. I was nervous originally because the pink hearts and red balloons are so similarly colored, but it actually worked out beautifully.
I chose this Irish Cream and marshmallow frosting because it doesn’t dry out quickly. This gives you ample time to decorate your cake. In total, the application of the lucky charms marshmallows should take about twenty to thirty minutes for a six inch cake.
Lucky Charms Cake Recipe
This lucky charms cake recipe is actually very simple. In order to achieve the green ombre effect with the three layers, this St. Patrick’s Day cake uses a white cake as a foundation.
Normally white cake is made with almond extract. However, that doesn’t really jive with the vanilla flavor of the lucky charms marshmallows or the marshmallow frosting. Instead, we’re adding a hint of coffee extract and some Irish Cream. Not only does this lucky charms cake look like St. Patrick’s Day, but it tastes like it too.
Thank you so much for stopping by!
Lucky Charms Cake with Irish Cream Frosting
Ingredients
- 1 cup unsalted butter, room temperature
- 2 cups granulated sugar
- 7 large egg whites, room temperature
- 1 teaspoon vanilla extract
- 1 teaspoon coffee extract
- 2 ¾ cups cake flour
- 2 teaspoons baking powder
- 1 teaspoon salt
- 1 cup whole milk, room temperature
- green food coloring, as needed
- 1 family sized box of lucky charms cereal
Irish Cream Marshmallow Frosting
- ¾ cup (3 sticks) unsalted butter, softened
- ½ teaspoon salt
- 2 cups confectioner's sugar, sifted
- 2-5 Tablespoons Irish Cream, as needed
- 1 jar of marshmallow fluff
Instructions
Cake
- Prepare the cake layers by lightly oiling the insides of three 6” cake pans. Place a parchment round in the bottom of each pan (see note) and rub oil on it. Preheat the oven to 350°F
- Combine the butter and sugar in the bowl of a stand mixer fitted with the paddle attachment. Beat on medium-high speed for 3-5 minutes, or until it is fluffy and light in color.
- Stop the mixer, scrape down the sides and then put the mixer on a low speed. Incorporate the egg whites one at a time until completely combined, scraping down the sides as needed. Add in the extracts until just combined.
- Whisk together the flour, baking powder and salt in a bowl. Add half of the flour to the butter mixture and stir until combined. Add in the milk until completely integrated, then finish with the last of the flour.
- Separate the batter evenly into three containers. Add some green food coloring into the first container, a little more to the second and twice as much into the last. Stir until blended completely and pour into prepared cake pans.
- Bake in the preheated oven until a toothpick inserted in the center comes out clean, about 25 minutes. Allow the cake layers to cool in the pan until the edges start to separate from the sides of the pan. This takes about 10 minutes Turn out onto wire racks to cool completely before frosting.
Irish Cream Frosting
- Beat the butter with a paddle attachment on high speed until creamy and fluffy, about three minutes. Scrape down the sides, add the salt and powdered sugar and beat on medium for another two minutes. Reduce the speed to low and add in the marshmallow fluff and Irish Cream. If the consistency is not spreadable, add one tablespoon of Irish Cream at a time until the frosting has thinned out.
Assemble
- Separate the marshmallows from the cereal, placing them in individual containers based on shape.
- Separate the frosting into fourths. Place one cake layer on a cake plate or stand and evenly spread one of the frostings onto the layer. Don't be nervous if it starts spilling over the side. Repeat the process with the rest of the layers, reserve one frosting for later.
- Using a spatula or bench scraper, scrape the excess frosting from the top and sides of the cake. Make the crumb coat very thin. Smooth the edges of the top layer as needed to make them flush with the top. Place it in the refrigerator to chill for 30 minutes (or freezer for 10).
- Remove the cake and spread the remaining frosting around the outside of the cake. Use a spatula or bench scraper to make it smooth.
- Following the pattern of the jingle, place the marshmallows in a single row all the way around the cake (see note). Start the next layer one marshmallow over from where you began previously (heart on top of stars). Repeat this process until the entire cake is covered.
- Sprinkle some of the crushed cereal from the bottom of the bag on top of the cake for texture. Cut, and serve.
Ed T. says
How strong is the coffee flavor? Would vanilla alone or another flavor in the cake go well with the irish cream frosting? Very excited to try this for a birthday cake!
Mackenzie Ryan says
Hi Ed! The coffee flavor is definitely present but not overpowering. If you're on the fence about using it, hazelnut, almond, or caramel all taste great with it as well. Let me know what you end up choosing! I hope you love it.
Ed T. says
I ended up adding a little coffee and everything worked out great. Delicious cake and frosting.
Mackenzie Ryan says
Oh yay! This makes me so happy!
Rachel says
This was an impressive treat to make for St. Patrick’s Day! I don’t have 6” cake pans and had the brilliant idea to bake in my sauce pots. It took 40-50 minutes though.
Mackenzie Ryan says
That's a very clever workaround, Rachel! I absolutely love the kitchen creativity you used to make this cake!
Christina Gilbert says
What Irish cream do you use? I have all of the ingredients but that not sure what to get?!
Mackenzie Ryan says
Hi Christina! I'm so excited you're making this cake. 😁 I usually use Bailey's Original Irish Cream, but any Irish Cream will work. There are copycat recipes for versions you can make at home, or if you don't usually use it, you can usually find the "sample" type bottles that are only 50 mL that will give you enough for this frosting.
I hope that helps. Let me know how it goes! I'd love to see a picture! 🙂
Mackenzie
Christina Gilbert says
Thank you! I have one more question can I use two 9 inch round cake pans instead of three 6 inch cake pans?!,
Mackenzie Ryan says
Yes you can, Christina, but it does mess with the chemistry a bit. It will make a significantly thinner cake, so it should bake a little quicker. Keep an eye on it about 15 minutes in, checking it with a toothpick to see if it's done. Also, because the cake is wider instead of taller, you'll still need the same amount of lucky charms marshmallows except the layers won't go quite as high up. Maybe 4-5(ish) lines high. You can always double the cake recipe to make up the height if needed. 🙂
CelticBrewer says
This only miss here is not making cereal milk for the milk addition.
Mackenzie Ryan says
I thought the same thing too, but when I made the recipe with cereal milk originally, it turned out WAAAAYYY too sweet. In order to get the right texture to the cake but not have it overpower it, I opted to go without the cereal milk. I've been fine tuning it each time I make it to make it work, but haven't gotten there quite yet.