Birthday Cake Marshmallow Recipe

This birthday cake marshmallow recipe is one of my favorites. These homemade marshmallows taste just like birthday cake, with plenty of rainbow sprinkles, too!

What Inspired This Birthday Cake Marshmallow Recipe?

“Birthday cake” or “cake batter” desserts seem to be having a bit of a moment on social media. I’ve spotted cake batter cookies, cake batter ice cream, cake batter doughnuts, protein bites, brownies, coconut macaroons, and oh so many birthday cake-themed French macarons.

Marshmallows offer endless room for creativity. You can experiment with different flavors and colors, cut them into fun shapes, or mix add-ins like candy, crushed cookies, sprinkles, or chocolate chips into the batter. It’s fun to create one-of-a-kind confections that you’ll never find in any supermarket.

For this recipe, I decided to experiment with the flavors and colors of a classic slice of birthday cake. With a fluffy marshmallow base, pale yellow color, cake batter flavor, and crunchy rainbow nonpareils sprinkles on top, this homemade birthday cake marshmallow recipe looks and tastes very much like the real thing.

Why Make Homemade Marshmallows?

The best thing about homemade marshmallows? They’re deceptively simple to make. Boil a few ingredients in a saucepan, pour the hot syrup into some gelatin, mix on high speed until fluffy, pour into a pan. That’s it. You can whip up a batch of homemade marshmallows in about 30 minutes of active kitchen time. (Although they take a good 12+ hours from start to finish, most of that is just passive resting time as you wait for the slab to set.) Make marshmallows that taste like rosewater, matcha, blueberry, or mint—you’ll never get tired of finding new color and flavor combinations to try.

And trust me. Once you’ve made your own marshmallows, it’s hard to ever go back to the store-bought kind ever again!

Birthday Cake Marshmallow Ingredients

To make birthday cake marshmallows, you’ll need:

• Gelatin – Gelatin creates the spongy, fluffy marshmallow texture. Although this recipe calls for powdered gelatin, these marshmallows can just as easily be made with leaves as well. See this post for conversions and other helpful hints.
• Granulated Sugar – Along with light corn syrup, granulated sugar gives homemade marshmallows their sweetness. To substitute caster sugar, measure by weight rather than volume. 
• Corn Syrup – I test most of my homemade marshmallow recipes with Golden Barrel, but you can also use Light Karo Syrup. Liquid glucose will also work.
• Salt – A small amount of fine sea salt (or table salt) cuts the sweetness of the marshmallow.

• Cake Batter Flavoring – I purchased a bottle of cake batter flavoring from LorAnn Oils, but there are a number of cake batter oils and extracts available on Amazon. Feel free to experiment to see which one works best for you. (And save the rest of the bottle to make my birthday cake ice cream recipe, too!) You can also flavor your marshmallow fluff with vanilla bean paste, or even do a red velvet cake version! 
• Gel Food Coloring – I chose yellow gel food coloring to mimic the colors of a slice of yellow cake, but you can also tint your marshmallows pink or blue, or omit the food coloring for a more natural look.
• Rainbow Nonpareil Sprinkles – You’ll need plenty of rainbow nonpareils sprinkles for the fluff and the crunchy coating. I suggest buying your sprinkles in bulk—supermarkets usually only sell sprinkles in small containers, and buying the 2-3 of them you’ll need for this recipe as isn’t cost-effective as purchasing a bulk bag. As a bonus, you can use the extra sprinkles to make slice and bake rainbow heart cookies, miniature dot cakes, or a cake roll with funfetti buttercream.
• Potato Starch and Confectioner’s Sugar – Potato starch and confectioner’s sugar (icing sugar) create the powdery coating that prevents the marshmallows from sticking together. If you can’t find potato starch, you can replace it with an equal amount of cornstarch (cornflour).

Birthday Cake Marshmallow Recipe Tips & Tricks

Add sprinkles, then remove. If you want to coat one side of the marshmallow slab in sprinkles, do it before you remove your slab from the metal tin. It’s much easier (and less messy!) to pour the sprinkles on top of the marshmallow mixture while it’s still in the tin. The top of the slab will also be the stickiest, since it hasn’t been coated in oil.

Cut creatively. You can cut your marshmallow slab any way you’d like. Six rows of six works well for 36 average-sized marshmallows. Or, you can cut four rows of four 16 large (brownie-sized!) marshmallows. Alternately, you can use a well-oiled metal biscuit cutter to cut the slab into shapes—see my strawberry heart marshmallows for an example.

Use a candy thermometer. Do not attempt this recipe without a candy thermometer. I love this one, by Taylor.

Oil your knife. Before slicing, coat your chef’s knife in vegetable or olive oil, and keep the bottle nearby so you can reapply as necessary. Using a sharp, well-oiled knife makes slicing the sticky marshmallow slab so much easier.

Make-Ahead and Storage Suggestions

Layer birthday cake marshmallows between sheets of wax paper or parchment. Store in an airtight container at room temperature for up to three weeks.

Other homemade marshmallow recipes you might enjoy:

Mint Chocolate Chip Marshmallows
Cookies and Cream Marshmallows
Strawberry Marshmallows
Classic Vanilla Bean Marshmallows
Watermelon Marshmallows

And if you do make these, or any of my recipes, don’t forget to tag me @bastecutfold or use the hashtag #bastecutfold on Instagram. I always love to see what you’re making!

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