Preheat your oven to 325°F. Line a large rimmed sheet pan with parchment paper — this prevents sticking and makes cleanup effortless.
In a large bowl, combine the rolled oats, hemp seeds, chia seeds, pumpkin seeds, pecans, roughly chopped, salt, and cinnamon. Stir until the seeds and nuts are evenly distributed through the oats.
In a small bowl, combine almond butter, maple syrup and oil until smooth.
Pour wet mixture over the dry ingredients. Stir thoroughly with a spatula until every oat and seed coated — no dry pockets at the bottom of the bowl.
Transfer the mixture to your prepared sheet pan. Spread it into an even layer, then use the back of a spatula or measuring cup to firmly press it down. This compacting step is the real secret to getting big, bakery-style clusters instead of granola dust.
Bake at 325°F for 20-25 minutes, or until the edges are deep golden brown and the center is fragrant and toasted.
Remove from the oven and let the granola cool completely on the pan. Do not stir it while it cools — this is the single most important step for keeping your clusters intact.
Once fully cooled, break the granola into clusters of your preferred size. Store in an airtight container at room temperature for up to 2 weeks, or freeze for longer storage.