01 -
Spray glass pan with cooking spray.
02 -
Melt butter in saucepan over low heat. Add 5 cups marshmallows, stir until melted.
03 -
Remove from heat. Stir in cereal and remaining marshmallows.
04 -
Pour into pan, press down with parchment paper.
05 -
Optional: Melt white chocolate in microwave, drizzle over bars.
06 -
Cool to room temp, chill 10 minutes if adding chocolate.