Place garbanzo beans, 1 1/2 tablespoon reserved aquafaba, and lemon juice in a food processor. Let soak until flavors combine, about 15 minutes.
Pulse soaked garbanzo beans until roughly chopped. Add tahini, olive oil, garlic, cayenne, sugar, salt, and black pepper; blend, thinning with reserved aquafaba, until hummus is smooth and reaches desired consistency.
