Cut the cauliflower head into large florets. Add cauliflower florets to a food processor and process for a few seconds until riced and no large chunks remain.
In a mixing bowl, beat the eggs together with a fork. Add the riced cauliflower, almond flour, cheeses, garlic powder, salt, and pepper. Mix everything together very well, making sure the egg is completely mixed through the mixture. Set the mixture aside for 10 minutes.
While the mixture is sitting, heat a large non-stick pan over medium-high heat. Once hot, add the olive oil. Scoop out a 1/4 cup of the cauliflower fritter mixture and place it into the pan. Use the back of a spatula or bottom of the 1/4 cup measurement to flatten out the fritter mixture until it is about 1/2 an inch thick. You can fit around 2 - 3 fritters into the pan at once.
Fry on each side for about 5 - 7 minutes before flipping. Be very careful not to flip too early as the fritters are quite fragile while cooking in the beginning.
Once fully cooked, remove and place on a wire rack to allow any excess oil to drip off. The fritters will also become less fragile and more crispy as they cool.
Garnish your fritters with a spoonful of sour cream and some freshly chopped green onions and enjoy!