Preheat the oven to 350 F. Spray rimmed cookie sheet with non-stick cooking spray, or line with a silicone baking mat.
In a small mixing bowl, whisk together the melted butter, maple syrup, and vanilla.
In a larger mixing bowl, toss together the quick cooking oats, rolled oats, chia seeds, pea protein powder, cinnamon, and finely chopped nuts.
Pour the maple-butter mixture over the oat mixture and mix together.
Spread the granola onto the prepared cooking sheet and press into an even layer to cover the bottom.
Place in the preheated oven and bake for 10 minutes.
Then turn off the oven after 10 minutes and let the granola finish cooking as the oven cools down. It's ready to eat the next morning, or about 3 hours later when the oven has cooled down and properly dried out the granola.
Use a metal spatula to loosen and break the granola into chunks for serving. Serve High Protein Overnight Granola with milk or high protein Gerek yogurt and some fresh fruit.