Preheat the oven to 425 degrees Line a baking sheet with parchment paper.
In a small food processor, pulse the chickpeas and parsley until coarsely chopped. Alternatively, you can hand chop the parsley and use a fork or potato masher to turn the chickpeas into a paste. Transfer to a medium mixing bowl and add the quinoa, almond flour, cumin, coriander, cayenne, and sea salt; stir until well-incorporated.
Lightly grease the parchment paper with oil. Also, grease a 1/3 cup measure and use it to portion the quinoa falafel batter into 8 mounds. With your hands, shape the quinoa into balls, then pat into 1-inch thick smooth discs and arrange an inch or so apart on the parchment-paper lined baking sheet. Transfer to the oven and bake until the patties have dried out and formed a nice brown crust on the bottom, 30 minutes. Flip the burgers and return to the oven for 10 more minutes, until firm.
While the burgers bake, prepare the tzatziki. In a small food processor, puree the cucumber, parsley, lemon juice, yogurt, and salt until smooth but still chunky. Alternatively, you can finely chop by hand.
Top the cut-side of each bun with 1 tablespoon of tzatziki. Add a falafel quinoa burger patty to the bottom half and top with another spoonful of tzatziki and a handful of herb leaves. Repeat with the remaining burgers and enjoy immediately. Or refrigerate each element separately for later.