Preheat oven to 325. Prepare a large baking sheet with a silicone baking mat or parchment paper.
In a bowl, mix together oats, crispy rice cereal, and salt. Set aside.
In a microwave-safe dish, heat Nutella and honey together for about 20 seconds or until thin enough to stir together easily.
To a blender, add Nutella and honey mixture, melted butter, and mashed banana. Blend until smooth. Pour over oat mixture and stir until coated.
Spread granola onto the baking sheet in one layer. Bake in oven for 15 minutes. Flip granola over using a spatula (this won't be perfect, just flip it in segments). Bake for another 10-15 minutes until mostly dry (will dry out more as it cools) and beginning to brown.
Let cool on cooling rack then crumble. Store in an airtight container.