We Tested A Bizarre Hack For The Marshmallows In Lucky Charms Cereal

We may receive a commission on purchases made from links.

Picture yourself roaming the hills and forests of Ireland. The lush green grass, the bright blue sky, and suddenly, at long last, you happen upon Lucky the Leprechaun. Finally, you can get those coveted Lucky Charms. Sure, you can enjoy a bowl of Lucky Charms the traditional way with some milk, or you could try the viral food hack that blew up on TikTok. Maybe you've seen it: Someone microwaves a bowl of Lucky Charms for precisely 18 seconds, and the marshmallows seem to quadruple in size. Cool, huh? Yeah, well, hold that enthusiasm.

I recently ventured to the cereal aisle at my grocery store and picked up a box of Lucky Charms, which are also available on Amazon, eager to experience the bounty of enormous, fluffy marshmallow treats for myself. Following the directions laid out in a number of viral videos, I filled a microwave-safe bowl halfway with the cereal and then microwaved it for 18 seconds, no more and no less. The air smelled sweet and promising, and I opened the door on the second beep, grabbed the warm bowl, and looked down disappointedly at regular-sized Lucky Charms marshmallows. I tried another 10 seconds. Then another. Then 30 seconds. Once they had microwaved for a solid minute and the bowl was nearly too hot to hold, I had to give up in defeat. There would be no mighty marshmallowy treats for me.

In the videos featuring massive marshmallows, you'll notice right away that something is a little off. Many of the colors don't quite match real Lucky Charms, but the shapes are oddly consistent. If you've ever toasted a real marshmallow before, you know they morph as they expand and become big, puffy blobs. You don't turn a little horseshoe marshmallow into a big horseshoe marshmallow. This was a prank video from the beginning. The first video appears to have been uploaded by Cereal Life on TikTok on April 1, 2025. But it spread beyond April Fool's Day, and a flicker of hope that it was real remained.

Much like the deliciousness of Rice Krispies treats, which merge crispy cereal with gooey marshmallow, this would-be hack promised something new and exciting. Plus, in all fairness, I was unsure what freeze-dried marshmallows might do in the microwave. At the cost of a box of cereal, it was worth a try to see if it would do anything even close to what the videos show, but sadly, it did not. In fact, the microwaved marshmallows didn't even get warm.

Normal marshmallows have a lot of air and moisture trapped inside. When you warm them, the air and moisture expand while the sugar softens, making the entire structure larger. A freeze-dried marshmallow has lost most of the air pockets and moisture, meaning there's very little to react with the heat of the microwave. That's why they don't expand anywhere near as much as normal marshmallows. This little joke was always too good to be true.