Preheat oven to 250°F. Place almonds, pumpkin seeds, pecans and walnuts into a food processor and pulse a few times to chop the nuts and seeds into smaller pieces. Don't process too much because you still want some chunky pieces.
Transfer the nut mixture into a large bowl, add all remaining ingredients except the dates and stir well. Spread an even layer of the mixture onto a large parchment-lined baking sheet. You may need two sheets if you’re baking sheets aren’t oversized like mine.
Bake for 35 minutes. Remove from oven, add dates and give the mix a good stir. Bake for 25-30 minutes more or until granola is golden brown in color. Remove from oven, let cool and enjoy. It will get crunchier as it cools. I recommend storing any leftovers in a Mason/Weck jar in the fridge. It will stay extra crunchy this way.