Line a 9x9 inch baking pan (or 13x9 for thinner treats) with parchment paper and set aside.
Then, place the marshmallows and butter in a large microwave-safe bowl. Microwave on high for 60 seconds and then stir well and then microwave for another 30 seconds.Stir until smooth and the marshmallow and butter are well combined. If needed, microwave for an additional 30 seconds until marshmallows are melted.
Add the cereal and mix until the cereal is evenly coated with marshmallow and butter mixture.
Turn the coated cereal into the prepared pan gently (see tips in post) pressing it into an even layer.
Allow the treats to set at room temperature for at least an hour before cutting.
Notes
TIPS:
Fresh Marshmallows. For the best results use a fresh bag of marshmallows and cereal. If either of these ingredients is stale you will end up with stale-tasting treats.
To prevent stickiness. You can spray your spoon and hands with non-stick spray to help prevent the melted marshmallows from sticking when mixing and pressing the treats into the pan.
Be gentle with pressing the treats in the pan, using a light hand. Pressing too much or too hard may result in tough Lucky Charm treats.
Extra gooey marshmallow treats. If you'd like, you can set aside some marshmallows from the cereal and press them into the top of the treats before they set.
STORAGE:Store any leftover treats in an airtight container at room temperature for up to three days. Keep in mind that these treats tend to get stale faster than traditional rice krispies treats.