01 -
Line 9-inch square baking dish with parchment paper.
02 -
Melt butter, add all but 1 cup marshmallows. Stir until melted over low heat.
03 -
Remove from heat, add vanilla. Stir in cereal and remaining marshmallows.
04 -
Press gently into pan with wet fingers. Let set 1 hour before cutting.