After much trial and error, this is my *official* recipe for truly crispy sweet potato fries. They're easy to fill up on (delicious and high in fiber), but you're getting tons of vitamin A and other nutrients so it's all good.
Peel the potato and (carefully!) cut it into 1/4-inch wide sticks, making sure they’re as close to the same size as possible for even cooking. You may need to slice off some edges to even them out.
Soak the fries in a large bowl filled with cold, slightly salted water for about 45 minutes (or as long as you have - at least give them a good rinse).
Move a rack to the top position of the oven and preheat it to 400 F. Put a cooling rack on a large cookie sheet (I use 13”x17”). You can also line it with parchment paper but you probably won't get the same crispiness. If you don’t have parchment, put the fries directly on the pan (don’t use foil).
Drain the fries and dry them well. In the same large bowl (wiped dry), toss the fries with the starch. Drizzle in just enough oil to lightly coat the fries, and toss again. Sprinkle in the paprika, garlic powder, salt and cayenne if using; toss.
Spread the fries in an even layer on top of the cooling rack. Make sure they’re evenly spaced - if the pan is too crowded, you’re better off baking them in batches. Bake at 400 F for 25-30 mins (if you're not using a cooling rack, flip them halfway). Then broil on high for about a minute, watching them closely. When they start to puff up and get slightly charred, they're done. Enjoy asap!
Notes
*It's tricky to give an exact size or weight since potatoes come in such different shapes, but try to find one (or two) that looks like it'll make nicely shaped fries of about 4 inches long. In the photos above, I had one really big potato so I cut it in half lengthwise first.**I keep a bag of Bob's Red Mill Arrowroot Starch in my fridge and use it as a 1-1 replacement for cornstarch, which is super processed. Arrowroot starch is tasteless and serves the same purpose. It's definitely more expensive, but you only need a tablespoon or two at a time (for very few recipes).If you love sweet potatoes, try my BBQ Sweet Potato Pizza!