Grease the 8x8-inch baking dish with butter or line it with parchment paper.
Place Oreo cookies in a zip-top bag and crush them into small pieces using a rolling pin or the back of a spoon. Set aside.
In a large saucepan, melt the butter over low heat.
Once the butter is melted, add the marshmallows to the saucepan. Stir constantly until the marshmallows are completely melted and smooth. Mix in vanilla and salt.
Remove from heat. Stir in Rice Krispies and 3/4 crushed Oreos until fully coated.
Spread the mixture into the prepared pan. Use a spatula or wax paper to press evenly.
Sprinkle with remaining crushed Oreos. Press lightly so they stick.
Let cool for 30 minutes, then slice into 12 squares.
Notes
Use different types of Oreos to add varied flavors to the treat. You can try golden Oreo, mint Oreo, or even peanut butter Oreo.
Use only 3 ½ cups of cereal for gooier treats.
Add white chocolate chips or drizzle melted chocolate for extra indulgence.
These keep well at room temp for 3–4 days in an airtight container.