Invite friends to make the toppings for an indulgent ice-cream potluck party—peanut brittle mixed with crispy rice cereal, fresh blueberry sauce and an over-the-top mix of crushed chocolate-covered pretzels, cookie crumbs and more.
Line a rimmed baking sheet with parchment and spray the paper with nonstick cooking spray. In a medium saucepan, combine the sugar, corn syrup and water and bring to a boil over moderately high heat. Cook undisturbed until a deep-amber caramel forms, about 7 minutes. Remove from the heat. Stir in the rice cereal, banana chips, peanuts and baking soda.
Quickly spread the brittle on the baking sheet, separating it into pieces as much as possible with a spatula. Let cool until hardened, about 45 minutes. Coarsely chop the brittle or break it into clusters and serve.