In a saucepan, melt the butter, Nutella, and chocolate chips over medium-low heat, stirring occasionally. Remove from the heat.
In a large bowl place the Crispix and pour the melted chocolate mixture over the top. Gently stir well to coat evenly. Sprinkle with the powdered sugar and cocoa and toss to coat. Store in an airtight container.
Yield: Beaucoup, or about 12 cups