No-Bake Chewy Oreo Bars are dessert bars that are made with a mixture of chopped Oreo cookies, mini marshmallows, and butter.
Spray an 8x8-inch baking dish with nonstick cooking spray or line with parchment paper. Set aside.
In a large microwave-safe bowl, combine marshmallows and butter.
Melt the marshmallows and butter in the microwave in 30-second intervals, stirring in between, until melted (about 2 minutes).
Add chopped Oreos (reserving ¼ cup for the topping) to the marshmallow mixture and stir.
Pour mixture into the prepared 8x8-inch pan and press into the pan with a spatula. Top with reserved chopped Oreo cookies.
Place pan in the refrigerator to set for at least 2 hours, up to overnight.