Prep the Pan: Line an 8x8 inch baking pan with aluminum foil and grease the foil with butter. Set aside.

In a large bowl combine the Dry Ingredients: Rice Krispies cereal, Teddy Grahams, and chocolate chips.

In a large saucepan over medium-low heat, combine the marshmallows and butter. Stir constantly until the marshmallows are completely melted and the mixture is smooth.

Remove the saucepan from the heat, Stir in Vanilla then immediately pour the marshmallow mixture over the cereal mixture. Stir until all ingredients are well combined.

Press and Cool: Transfer the mixture to the prepared baking pan and press down firmly to compact it. Allow to cool completely before cutting into squares.