Preheat your oven to 350 degrees Fahrenheit. Grease a 9x13 inch baking pan or line it with parchment paper, leaving an overhang for easy removal.

In a large bowl, whisk together the melted butter and sugar. Add the eggs one at a time, followed by the vanilla. Sift in the cocoa powder, flour, and salt. Fold gently until just combined. Do not overmix.

Pour the batter into your prepared pan and smooth the top. Bake for 25 to 30 minutes. The center should be set but still moist. Let this layer cool completely.

While the base cools, mix together the 1 1/2 cups of peanut butter, 1/2 cup of melted butter, and powdered sugar until smooth. Fold in the crispy rice cereal. Spread this mixture evenly over the cooled brownies.

In a microwave-safe bowl, combine the chocolate chips and the remaining 1/2 cup of peanut butter. Heat in 30-second intervals, stirring until glossy and smooth. Pour this over the crunch layer.

Place the entire pan in the refrigerator for at least 2 hours. This ensures the squares are firm enough to cut into perfect squares. Sprinkle optional add-ins before the chocolate sets if desired.

Cut into squares once chilled and serve with milk or coffee for the best experience.