Cap'n Crunch Milkshakes

Combine cereal and milk in a large measuring cup (or medium bowl). Stir, then refrigerate for at least 20 minutes and up to 1 hour to infuse the cereal flavor. Add infused cereal-milk mixture to a blender along with 2 tablespoons peanut butter and as much as ice cream as desired. Blend until thick and smooth. To decorate serving glasses, spread remaining peanut butter along the rims of the cups, then roll in Cap’n Crunch crumbles. Pour milkshake into glasses, top with whipped cream and drizzle with melted peanut butter, if desired.