Combine the water and lemon juice in a small bowl. In a separate bowl, whisk the tahini and oil together until smooth. Set aside a small handful of chickpeas to use for garnish.

Process the remaining chickpeas, garlic, salt, cumin, and cayenne in a food processor until they are nearly ground, about 15 seconds. Scrape down the bowl with a rubber spatula to ensure no large pieces are left behind.

With the processor running, pour the lemon juice mixture through the feed tube in a steady stream. Continue to process for 1 minute until the mixture is quite smooth.

Add the tahini mixture in a steady stream while the machine is still running and process until the hummus is creamy and pale, about 15 seconds.

Transfer the hummus to a serving bowl and cover with plastic wrap. Let it sit at room temperature for 30 minutes to allow the flavors to develop.

Sprinkle the top with the reserved chickpeas and cilantro, then finish with a drizzle of oil before serving.