Set Aside Cereal. Start by pouring the cereal into a large bowl (use your biggest bowl!). If desired, set aside 1/3-1/2 cup of the Lucky Charms marshmallows to sprinkle on at the end.

Melt The Mallows. Add butter and mini marshmallows to a saucepan, and stir over medium-low heat or medium heat. If your mixture doesn’t seem to be coming together, use a whisk to mix it. It should pull together easily!

Stir In Vanilla & Salt. Quickly stir in the vanilla extract and kosher salt and stir to combine.

Pour Marshmallow Mixture Over The Cereal. Next, pour the melted marshmallow mixture over the cereal and use a flexible silicone spatula to gently stir.

Stir To Coat. Use the spatula to gently mix until the cereal is evenly coated in the marshmallow mixture (it will be sticky!)

Pat Into Pan. Transfer the cereal mixture to your prepared baking dish and use very gentle pressure to pat the mixture into an even layer. Sprinkle with reserved Lucky Charms marshmallows if desired.

Cool & Cut. Let the Lucky Charms Treats cool and set before cutting into 9 large squares, 12 rectangles or 16 small squares.

Store. Transfer leftover cereal bars to an airtight container or bag and store at room temperature 4-5 days. They'll stay even more fresh if you individually wrap the squares in plastic wrap first!