Line a 9x9 baking dish with a parchment paper sling or butter for easier removal. Set aside.

Melt butter in large saucepan over medium heat.

Add jumbo marshmallows to melted butter. Continue to stir and gently melt over medium heat until marshmallows are melted and smooth.

Remove from heat and stir in vanilla extract. Add Rice Krispies, Golden Grahams, and 1 1/2 cups of miniature marshmallows. Stir until cereal is evenly coated with melted marshmallow mixture.

Transfer half of the cereal mixture into the prepared pan, then sprinkle with half of the chopped Hershey's bars and half of the remaining 1 cup of miniature marshmallows.

Add remaining cereal mixture then press gently into the pan to compact slightly. Be careful not to compress the treats too much though or they will be dense and hard. Top with remaining Hershey's bars and marshmallows.

Cut into small squares to serve.