Preheat the oven to 400 degrees F (200 degrees C).

Poke holes all over sweet potatoes with a fork.

Roast sweet potatoes in the preheated oven until soft, about 45 minutes; let cool. Cut sweet potatoes in half lengthwise.

Combine garbanzo beans and olive oil in a blender and pulse several times to mash. Scoop flesh out of sweet potato peels and add to the blender; pulse to combine. Add tahini, lemon juice, lemon zest, cumin, coriander, white pepper, and sea salt to mixture; blend until smooth, adding reserved garbanzo bean liquid as needed to make a smooth, creamy hummus.