Line a 9x9-inch baking dish with parchment paper. Set aside.

To a large pot over medium-low heat, add chocolate chips, 0.75 cup peanut butter, and butter. Stir frequently until melted and smooth.

Add marshmallows, stirring frequently until melted. Once melted, remove from heat.

Spray a clean rubber spatula with nonstick spray to prevent sticking. Using the spatula, fold in the Cocoa Krispies cereal. Stir until well-coated.

Transfer the mixture to the prepared baking dish, pressing it into an even layer.

Add the remaining 0.25 cup peanut butter to a microwave-safe bowl. Heat for about 20-30 seconds. Drizzle over the bars.

Allow the bars to cool completely at room temperature or in the refrigerator for at least 45 minutes before cutting and serving.