Cut cauliflower into florets and cook in boiling water until tender, about 10 minutes.
Drain and mash the cauliflower while it is still warm.
Stir in the cheese, eggs, green onions, bread crumbs, cayenne & salt. Adjust seasoning to taste. (Start with the lower amount of cheese, breadcrumbs, cayenne, and salt. Add more as needed for taste and binding the pancake mixture together.)
Coat the bottom of a skillet with olive oil over medium-high heat.
Form the cauliflower mixture into patties about 3 inches across.
Cook until golden brown & set, about 3 minutes per side. Remove to a paper towel-lined plate to drain.
Serve pancakes on a plate and top with sour cream and more green onion, if desired.