Separate some of the Lucky Charm Marshmallows from the cereal. You will need a small handful for each bundt.
In a large pot, melt butter and mini marshmallows on medium heat. Make sure you stir every 15-30 seconds until the two ingredients are combined.
Add in Rice Krispy and Lucky Charm cereal and mix until everything is coated in the marshmallow mixture.
Put a handful of Lucky Charm Marshmallows at the bottom of each bundt.
Pack about 3/4 cup of cereal mixture on top of the marshmallows.
Put in the fridge for at least 30 minutes.
Use an offset spatula so remove the bundts.