Begin by buttering the bottom and sides of a 9X13-inch pan or spray with cooking spray. Set aside.

In a large saucepan, melt 1/2 cup butter on low or medium-low heat and let it cook until the butter begins to melt.

Add in the marshmallows and cook on low, stirring constantly until the marshmallows are mostly melted. Don't worry about getting it perfectly smooth, it's perfectly okay if there are still some lumps left. Add the 1 tsp vanilla, pinch of salt and stir to combine.

Remove the pan from the heat and add the rice krispies in slowly while stirring, then the crushed Oreos. Stir until evenly combined. Make sure to scrape up the bottom & edges of the pan really well to incorporate all the ingredients.

Scoop the mixture into the prepared pan and press the mixture into the pan with lightly greased hands or a sheet of parchment paper. Be sure to use a gentle hand if you want them chewy, pressing down too hard will result in too firm of treats). Let cool before slicing into squares & enjoy!