Line an 8x8-inch baking pan with parchment paper and set it aside.
Chop your graham crackers into bite-sized pieces.
In a large mixing bowl, combine the crispy rice cereal, chopped graham crackers, chocolate chips, and an extra handful of mini marshmallows, tossing them together to mix evenly.
In a separate large pot or saucepan, melt the butter over medium-low heat until it is completely liquid. Add the 10 oz of mini marshmallows to the pot and stir continuously over medium-low heat until they are completely melted, smooth, and fluffy.
Remove the pot from the heat and immediately stir in the vanilla bean paste until fully incorporated. Working fast, pour the warm melted marshmallow mixture over your cereal and chocolate mix.
Use a greased spatula to gently fold the ingredients together until everything is evenly coated in the sticky marshmallow mixture. Transfer the mixture into your prepared 8x8 pan and press it down lightly into an even layer without packing it down too firmly.
Scatter a handful of extra chocolate chips across the top while the treats are still slightly warm, pressing them gently so they stick to the surface.
Allow the treats to sit and cool at room temperature for 2 hours, or speed things up by placing the pan in the fridge for 40 minutes. Slice the set treats into 16 even squares.
If you are adding the optional topping, spoon or pipe 1 tablespoon of marshmallow fluff onto each individual treat just before serving. Use a kitchen torch to carefully brulee the fluff until it is golden brown and toasted, then enjoy immediately.
Store any remaining untopped treats in an airtight container at room temperature.