In a large saucepan, melt the unsalted butter over medium heat. Once melted, add the creamy peanut butter and stir until smooth and well combined.

Remove the saucepan from heat and stir in the vanilla extract and salt.

Gradually add the powdered sugar to the peanut butter mixture, stirring until fully incorporated and smooth.

Fold in the crispy rice cereal until evenly coated with the peanut butter mixture.

Line a 9x13-inch baking dish with parchment paper, leaving some overhang for easy removal. Pour the mixture into the prepared dish and press it down firmly with a spatula or your hands.

In a microwave-safe bowl, melt the semi-sweet chocolate chips in 30-second intervals, stirring in between until completely melted and smooth.

Pour the melted chocolate over the pressed cereal mixture and spread it evenly with a spatula.

Allow the bars to cool at room temperature for about 30 minutes, then refrigerate for an additional 1 hour to set.

Once set, lift the bars out of the dish using the parchment paper and cut into squares.