Preheat the oven to 425 degrees F. Cut the peeled sweet potatoes lengthwise into 1/4 inch sticks and place in a large gallon ziplock bag.
Add the salt, pepper, cornstarch, paprika, garlic powder, onion powder, and oil. Make sure to leave air in the bag, zip, and shake until the fries are evenly coated.
Line 2 cookie sheets with parchment paper and spread the fries between both sheets in an even layer- leaving space between each fry. You do not want to create steam as it will cause the fries to get soggy. Do not crowd the sheets.
Bake for 20 minutes on one side and then flip. Bake them for another 10-15 minutes until crispy and golden brown. Be sure to watch them carefully as the cooking time can depend on the thickness and heat of your oven.
Remove from the oven and spinkle with sea salt and parsley. Allow the fries to cool for 5 minutes and enjoy immediately!