Preheat oven to 320°F. Line a baking sheet with parchment paper or a silicone mat*.
Add date paste, tahini, vanilla extract, lemon juice, and lemon zest to a large mixing bowl. Mix until well combined and a uniform paste forms. If your paste is very thick, add 1 tbsp water to thin it out. It should be easy to mix but thicker than cake batter.
Add oats, nuts, seeds, and cinnamon. Mix well to combine and evenly disperse the ingredients.
Transfer granola to the lined baking sheet. Spread it out into an even layer and press down with a spatula or spoon so the granola is tightly packed (this will help create clusters!).
Place in oven and bake for 15 minutes, then carefully flip the granola over, and continue baking another 10-15 minutes, until golden brown. Keep an eye on the edges as they tend to burn faster.
The granola will still be a little soft out of the oven but will firm up into crunchy pieces as it cools.
Notes
DATE PASTE: To make date paste, blend 1-4 tbsp water with about ¼ cup of pitted dates. The amount of water you need will depend on how dry your dates are, so start with 1 tbsp and add more as needed. You can make a large batch of date paste and store the leftovers covered in the fridge for 2-3 weeks.LEMON ZEST: 1 lemon will produce a subtle lemon flavor, so adjust to your tastes.NUTS/SEEDS: I used 1 tbsp each of poppy seeds, shredded coconut, chia seeds, and flax seeds; 1/4 cup each of pepitas, almonds, and pecans.