Preheat the oven to 350°F (175°C).
In a large bowl, combines the oats, chocolate chips, walnuts, raisins, salt, and cinnamon (along with orange zest or citrus peel if using). Stir together.
In a saucepan on medium heat, melt the peanut butter and honey. When they have melted together, whisk together with a fork. Pour over the oat mixture and mix together with a large wooden spoon until well blended. Towards the end, this can get a little hard to mix together, be sure to crush any clumps with the wooden spoon to mix in any dry oats that may be left.
Line a 9-inch square baking dish with parchment paper. Spread the mixture into the dish, using your hands or a spatula to evenly spread it out. Once spread out, firmly press the mixture down. I find that it’s easy to fold down any extra parchment paper on top of the mixture and then press with your hand, as it keeps your hands from getting too sticky.
Bake for 20 to 25 minutes, until golden brown.
Remove from the oven and let cool. Once cool, gently remove the entire block from the pan by lifting the edges of the parchment paper. Place on a cutting board and using a serrated knife, cut into small bars. Store in an airtight container.
Now, pack up, take on the trail and enjoy!