Step 1: Prepare the Pan
Line a 9×13-inch baking pan with parchment paper or grease it lightly with cooking spray. This makes removing the treats easier once set.

Step 2: Melt the Butter and Peanut Butter
In a large saucepan over medium heat, melt the butter and 1 cup of peanut butter together. Stir until smooth and fully combined.

Step 3: Add Marshmallows
Lower the heat and stir in the marshmallows. Continue stirring until the mixture is completely melted and gooey. Add the vanilla extract and salt, and stir to combine.

Step 4: Mix in the Cereal
Remove the pan from heat. Gently fold in the Rice Krispies cereal, stirring until all the cereal is coated evenly with the marshmallow-peanut butter mixture.

Step 5: Press into the Pan
Transfer the mixture to your prepared baking pan. Use a spatula or lightly greased hands to gently press the mixture evenly into the pan. Don’t press too hard, or the treats may become too dense.

Step 6: Make the Chocolate Topping
In a microwave-safe bowl, combine the chocolate chips and ½ cup peanut butter. Microwave in 30-second intervals, stirring between each round, until the mixture is completely melted and smooth.

Step 7: Spread the Chocolate Layer
Pour the melted chocolate mixture over the Rice Krispie base. Spread it evenly with a spatula.

Step 8: Add Optional Toppings
Before the chocolate sets, sprinkle with sea salt, crushed peanuts, mini chocolate chips, or drizzle with melted white chocolate if desired.

Step 9: Chill to Set
Refrigerate the pan for at least 1 hour, or until the chocolate is firm. For a softer texture, let the treats set at room temperature for 2–3 hours.

Step 10: Slice and Serve
Once set, remove the treats from the pan using the parchment paper. Cut into squares or bars with a sharp knife and serve.