Three creative ways to use up leftover marshmallow fondant
I made a couple of cakes for a school cakewalk last week, and ended up with leftover marshmallow fondant in four colors.
Thinking there must be some reasonable way to use it up, I googled. The results were… uninspiring. Essentially, the advice was either to save it, practice with it, or use it as fondant. 🤷♀️
If I used fondant more than once a year, saving it might make sense, but the odds of me wanting these specific colors seem low, and given that I already have a hard time fitting all my ingredients in my limited storage space, I don’t love the idea of devoting space to something I might find a use for in a year or two.
Practicing holds zero appeal, as I only ever use fondant as a means to an end and don’t enjoy working with it enough to care about getting better. #embracemediocrity
“Using it as fondant” mostly consisted of “make cookies and put it on top!” If I hadn’t come up with any better ideas, I might have gone with this one, but it isn’t very interesting.
What I did instead
Eventually it occurred to me that marshmallow fondant is basically concentrated sugar and should be able to be substituted for other sugar forms in a lot of recipes. I mean, yes, there’s also gelatin and some corn starch from the powdered sugar but still: mostly sugar.
So I decided to attempt three very different approaches: using it to make a different kind of fondant, using it in place of powdered sugar, and using it instead of a different sweetener. But not in that order. (And no, I did not need all this extra sugar-filled dessert around the house, but in the interest of science…)
Note that what follows is more about the concepts than any kind of recipe to follow!
1. Use it to make a fondant-based candy
When I was searching the googs, I came across an article that wasn’t about using fondant up but was instead educating about the fact that there are multiple kinds of fondant. It pointed out that peppermint patties and buckeyes are a form of “confectionary fondant”… and that got me thinking.
Buckeyes are basically peanut butter, butter, and powdered sugar. Could I use fondant instead of the powdered sugar?
Yes, yes I could.
Considering the colors of fondant I had on hand, I used the white and the yellow for this candy. I wasn’t sure how the fondant would balance out, so I started with a cup and a half of peanut butter and a stick of butter (half of what the recipe called for, but a full cup seems excessive), then added a roughly fist-sized ball of fondant.
I beat the tar out of it in my stand mixer using the paddle and it was fairly loose, so I added another ball of fondant. Further mixing (and adding the vanilla) gave me a nice workable “dough”; if it had still been too soft, I would have added some powdered sugar a bit at a time until it was stiff enough to work with.
I am too lazy to mess with rolling into balls and definitely too lazy to dip unless it’s absolutely crucial (i.e. I’m making it for someone else and there are prizes on the line). So I spread my peanut buttery dough into a 9-inch square pan lined with greased parchment paper, then melted three ounces of semi-sweet chocolate chips and spread that on top.
When it had hardened, I flipped it out onto a cutting board, put it back in the pan upside-down, and did another three-ounce chocolate spread. I left it at room temperature (warm, in my house) until it was solid-ish on both sides, then put it on the cutting board again, cut the slab into little cubes, and put it all in the freezer. After it was truly solid, my mister moved the little pieces into a food storage container which we’re keeping in the freezer (these bites are delicious cold!).

This was a clear win for fondant reuse. They’re reminiscent of a Reese’s Peanut Butter Cup (and would be even more so if I had used more chocolate, so consider that option!). The texture is great, the flavor is great, it was pretty easy, and now we can’t stop eating them.
If I had more white fondant to use up, I’d try a peppermint patty recipe (modified to make it equally lazy). I just couldn’t see doing it with a dark blue or an orange fondant, though, so I moved onto the next pair of ideas!
2. Use it to make an eyesore of a sticky bun (i.e. in place of other sugar)
You know how sticky buns (cinnamon rolls and the like) have a filling made up of sugar and flavorings? I thought fondant, rolled to the same size as the dough, would work nicely as a filling.
If you used a nice white fondant, or something in the brown family, it would be gorgeous and a perfect pairing with a warm cinnamon/nutmeg flavor.
However, my goal was to use up a ball of dark blue fondant.
I am not kidding about the “eyesore” part. My husband may have mentioned a Smurf massacre… repeatedly. You have been warned.
Knowing that the blue was going to be over the top no matter what I did, I still thought something blue should “taste blue.” My solution was to make a blueberry compote with extra cornstarch (to make it thicker and easier to roll).
For the dough, I used KAF’s tangzhong cinnamon roll recipe (this is such a good recipe!). I used about 2/3 of it for this project (I rolled the other 1/3 into six balls and baked them in a standard muffin pan). I rolled it out as directed (an 18″×8″ rectangle), rolled the fondant out to the same size, and put the fondant on top. I spread my blueberry compote on the fondant, and gingerly rolled it all up. (Easier said than done! The blueberries wanted to squish out and the whole thing was structurally unsound, as you’ll see in the slightly terrifying photos to come.)
I sliced the roll into 12 pieces and put them in a greased 11″×7″ casserole dish. (At this point, my hands looked like murdered blueberries themselves.) From there I followed the rest of the cinnamon roll recipe.


So the two obvious questions at this point:
- Were they any good?
- Would you ever do this intentionally?
To answer the first question: yes, they were delicious! We all ended up with blue mouths, but they were darned tasty. Great texture, nice flavor, sticky in all the right ways.
The second question is a little trickier. If I wasn’t aiming to use up fondant, I wouldn’t make fondant just to do this. Except… it turns out to be a great way to get swirls of color in, if that’s a goal of yours for some reason (say, a party theme). If I hadn’t added the blueberries, the rolls would have even looked fairly neat and been easier to work with than the average cinnamon roll. (I regret nothing, despite the blue-splosion.)
However, I still had one more ball of fondant to use up! And as my beloved mother says, “Anything worth doing is worth overdoing!” so…
3. Use it instead of powdered sugar to make frosting
I recently discovered that any buttercream frosting recipe can become a delicious marshmallow buttercream frosting recipe simply by adding melted marshmallows. It stands to reason that marshmallow fondant could contribute both the marshmallows and the powdered sugar to the equation!
I didn’t want to make buttercream, though, because cream cheese frosting is so, so good on sticky buns. My remaining fondant ball was orange, which clearly needed to have an orange flavor to have any kind of cognitive resonance, and orange goes nicely with both cream cheese and with blueberry. (Also recall: anything worth doing is worth overdoing.)
So I softened a stick of butter and a brick of cream cheese. I beat the cream cheese with the fondant until it was good and smooth, then added the butter. I threw in the zest of one orange, and maybe a tablespoon of orange juice (I drank the rest after I squeezed it). Again, I would have added powdered sugar if it needed more stiffness, but for sticky buns, I like a somewhat runny frosting (the better for oozing into all the crevices!).

When it was all layered up, I felt like I should have been watching a Broncos football game or something, but no complaints at all on the flavor or texture.
I’m confident it would work well with buttercream, too, for the record.
What else?
Honestly, given how well these three experiments turned out, I’d be willing to try fondant in all kinds of other applications.
I could see it playing nicely in a cookie dough (as long as you were patient in blending it with the butter), added to a smoothie or coffee drink (or a “unicorn” sweet-milk boba concoction), or taken full circle by turning it into frosting to mix with your cake scraps and shape into cake pops. I’d try it on toast or pancakes or oatmeal.
Ideally you’d find an application that suited the color but even if your combos are as garish as mine, sugar is sugar. Make things for children! Or just act like a child yourself and let creativity reign over style. 😉
If you end up making something interesting with your leftover fondant, leave a comment and tell me all about it.
You’re an absolute genius!! Thank you so much! I’m making a big celebration cake for a friend’s baptism tomorrow. I found out that I only had a bit of icing sugar for the buttercream, but I had a big hunk of white fondant sitting sadly in the cupboard, going to waste, leftover from my daughter’s birthday. I googled whether I could use it, found your post, and that have me confidence to use it. I have just made the smoothest, most delicious lemon buttercream, by beating up the fondant with butter, the bit of icing sugar I had, and lemon curd. I hate waste, and I hate going out in the cold when I am cosily at home baking, so this has made me doubly happy!
I didn’t see this for an unpardonable length of time, but I’m so glad you shared it. Now I am doubly happy, too!