You have a couple of options for mixing the rest of the ingredients. If you have a large enough food processor, add everything to the oats and blend until fully combined. The dough is heavy and thick, so a powerful food processor helps. If not, you can add the dates to the oats and blend to combine, then transfer to a large mixing bowl and mix in the rest of the ingredients by hand.
1 cup hemp seeds, 1 cup packed, soft pitted dates, 1/2 cup unsweetened fine shredded coconut, 1/2 cup tahini, 1/4 cup maple syrup, 1/2 tsp sea salt