Step 1 In a large bowl, mix together the grated, well-drained potato, sweet potato, parsnip and carrot. Add the eggs, flour, baking powder, salt, pepper and parsley and mix well.
Step 2 Pour one-fourth inch of olive oil into a large skillet and heat over medium heat until hot. To form each latke, use a one-fourth-cup measure or ice cream scoop to scoop up the mixture, then flatten it out in your palm, squeezing out the remaining moisture. Each latke will be about 4 inches in diameter.
Step 3Form and fry a few latkes at a time (being careful not to crowd the pan), cooking them until the edges are crispy and brown, 3 to 4 minutes on each side. Remove the latkes to a rack or paper-towel-lined plate, keeping them warm until all the latkes are fried. The latkes are delicious served with yogurt or sour cream.