In a medium saucepan, combine the sugar and corn syrup and cook on medium heat, stirring well, until boiling. Remove from the heat and stir in the peanut butter and chocolate-hazelnut spread.
Pour the cereal into a large bowl, then pour the peanut butter mixture over the cereal and combine well, covering all the cereal flakes.
Line a baking sheet with parchment paper. Using a cookie scoop, shape the dough into 2-inch balls and place on the prepared baking sheet about 2 inches apart.
Put the chocolate in a small microwave-safe bowl and microwave in 30-second intervals, stirring after each, until melted. Drizzle over the cookie balls. Serve.
