Whirl bacon, cream cheese, onion, jalapeños, green onion, and sour cream in a food processor, about 1 minute. Place in a large mixing bowl.
Stir hash browns, cheddar, flour, cornstarch, salt, eggs, and 3 tbsp. ground cornflakes into bacon mixture.
Line a baking sheet with parchment paper. Scoop up a scant 1/4 cup of potato mixture and roll into a ball. Drop ball into a bowl filled with 3/4 cup cornflakes and roll to coat (mixture will firm up once coated). Place on sheet and repeat with remaining mixture. Chill until ready to cook.
Heat 2 in. oil in a medium pot until it registers 350° on a deep-fry thermometer. Fry potato balls, a few at a time, until golden, 5 minutes per batch. Drain on paper towels. Sprinkle with parsley and serve with ranch dressing.
Note: Nutritional analysis is per potato ball without dip.