Dump frozen hash browns in a strainer and rinse with cold water until defrosted. Squeeze excess water out of hash browns and place in a medium bowl. Add in cheese, onion, garlic, chili powder, flour, egg, and salt and pepper, and stir to combine.
Make the avocado cream: in the bowl of a food processor, combine all ingredients and process until smooth. Scoop the mixture into a serving dish and set aside.
Preheat a skillet over medium to medium high heat. Add enough canola oil to coat the bottom of the pan with a thin layer of oil. Drop potato mixture by large tablespoon-full into the hot oil, then flatten with a spatula to make a flatter pancake shape. Cook until golden brown, about 2 minutes, then flip and cook until golden brown on the other side, another 1-2 minutes. Drain on a paper towel.
Serve warm pancakes with a dollop of the avocado cream and with green onions sprinkled on top.