Line an 8X8 square pan with parchment paper
In a large saucepan or dutch oven over medium heat, add the butter. Let melt and turn the heat to medium high until butter starts to sputter and brown. Mix with a nonstick spatula. Butter will begin to foam, smell nutty and change color, keep an eye on it and once butter is browned turn the heat to medium-low
Add in the 8 cups of marshmallows. You want the marshmallows to melt COMPLETELY before moving on to the next step. The mixture should look smooth and almost liquid
Add in the tahini, pistachio paste and salt and mix until mixture is smooth
Add in the rice krispies and the chopped pistachios and mix again
Remove from heat and continue mixing until thoroughly combined
Add in halva crumbles and extra 2 cups of mini marshmallows
Press into prepared pan
*If you choose to add the extra pistachio layer, add 1/2 mixture to the prepared pan and then top with pistachio paste. Use the spatula to smooth paste into an even layer and add the other 1/2 of the rice krispie mixture on top*
Sprinkle tops with extra chopped pistachios and flakey salt!
Slice and enjoy!