Line a 9x13-inch pan with foil or parchment and spray with nonstick cooking spray.

Measure out cereal and place in a large bowl.

Measure out 15 ounces (1 ½ packages) mini marshmallows and set aside.

Melt the butter in a large pot over medium low heat. Continue cooking the butter, stirring occasionally, until the butter browns. This will take 3-7 minutes depending on the size of your pan, but just watch it – it’ll foam then reduce and little brown flecks will form in the bottom of the pan.

Once the butter is browned, add the marshmallows and stir until melted. Remove from heat and stir in vanilla extract.

Add cereal and stir to coat with the marshmallow mixture. Stir in remaining marshmallows and immediately pour into prepared pan. Press firmly to compact. Tip: spray wax paper with nonstick cooking spray so you can press without it sticking to your hands.

Let set until firm then slice into bars. Store in an airtight container for up to 3 days. To freeze, let cool completely then cut into bars and wrap each individual bar in wax paper and freeze in an airtight container for up to 3 months.